Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 30, 2017	Jan. 26, 2018	Jul. 01, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	LSTR
Entity Registrant Name	LANDSTAR SYSTEM INC
Entity Central Index Key	0000853816
Current Fiscal Year End Date	--12-30
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		41,991,429
Entity Public Float			$ 3,563,911,000

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 242,416	$ 178,897
Short-term investments	48,928	66,560
Trade accounts receivable, less allowance of $6,131 and $5,161	631,164	463,102
Other receivables, including advances to independent contractors, less allowance of $6,012 and $5,523	24,301	18,567
Other current assets	14,394	10,281
Total current assets	961,203	737,407
Operating property, less accumulated depreciation and amortization of $218,700 and $190,374	276,011	272,843
Goodwill	39,065	31,134
Other assets	76,181	55,207
Total assets	1,352,460	1,096,591
Current Liabilities
Cash overdraft	42,242	36,251
Accounts payable	285,132	219,409
Current maturities of long-term debt	42,051	45,047
Insurance claims	38,919	26,121
Dividends payable	62,985
Accrued compensation	30,103	7,769
Other current liabilities	47,211	45,714
Total current liabilities	548,643	380,311
Long-term debt, excluding current maturities	83,062	93,257
Insurance claims	30,141	26,883
Deferred income taxes and other noncurrent liabilities	36,737	53,583
Equity
Common stock, $0.01 par value, authorized 160,000,000 shares, issued 67,740,380 and 67,585,675 shares	677	676
Additional paid-in capital	209,599	199,414
Retained earnings	1,611,158	1,512,993
Cost of 25,749,493 and 25,747,541 shares of common stock in treasury	(1,167,600)	(1,167,437)
Accumulated other comprehensive loss	(3,162)	(3,089)
Total Landstar System, Inc. and subsidiary shareholders' equity	650,672	542,557
Noncontrolling interest	3,205
Total equity	653,877	542,557
Total liabilities and equity	$ 1,352,460	$ 1,096,591

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Allowance on trade accounts receivable	$ 6,131	$ 5,161
Allowance on other receivables	6,012	5,523
Accumulated depreciation and amortization on operating property	$ 218,700	$ 190,374
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	160,000,000	160,000,000
Common stock, issued shares	67,740,380	67,585,675
Treasury stock, shares	25,749,493	25,747,541

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Revenue	$ 3,646,364	$ 3,167,634	$ 3,321,091
Investment income	2,498	1,502	1,396
Costs and expenses:
Purchased transportation	2,805,109	2,415,663	2,551,343
Commissions to agents	297,410	264,205	270,260
Other operating costs, net of gains on asset sales/dispositions	28,687	29,702	31,618
Insurance and claims	62,545	57,280	48,754
Selling, general and administrative	170,583	143,239	149,704
Depreciation and amortization	40,560	35,796	29,102
Total costs and expenses	3,404,894	2,945,885	3,080,781
Operating income	243,968	223,251	241,706
Interest and debt expense	3,166	3,794	2,949
Income before income taxes	240,802	219,457	238,757
Income taxes	63,806	82,107	91,068
Net income	176,996	137,350	147,689
Less: Net loss attributable to noncontrolling interest	(92)
Net income attributable to Landstar System, Inc. and subsidiary	$ 177,088	$ 137,350	$ 147,689
Earnings per common share attributable to Landstar System, Inc. and subsidiary	$ 4.22	$ 3.26	$ 3.38
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$ 4.21	$ 3.25	$ 3.37
Average number of shares outstanding:
Earnings per common share	41,938,000	42,112,000	43,664,000
Diluted earnings per share	42,024,000	42,236,000	43,813,000
Dividends per common share	$ 1.88	$ 0.34	$ 0.30

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Net income attributable to Landstar System, Inc. and subsidiary	$ 177,088	$ 137,350	$ 147,689
Other comprehensive income (loss):
Unrealized holding (losses) gains on available-for-sale investments, net of tax (benefit) expense of $(41), $13, ($109)	(73)	23	(199)
Foreign currency translation gains (losses)		376	(2,104)
Other comprehensive (loss) income	(73)	399	(2,303)
Comprehensive income attributable to Landstar System, Inc. and subsidiary	$ 177,015	$ 137,749	$ 145,386

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
OPERATING ACTIVITIES
Net income	$ 176,996	$ 137,350	$ 147,689
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property and intangible assets	40,560	35,796	29,102
Non-cash interest charges	253	238	218
Provisions for losses on trade and other accounts receivable	7,439	5,735	5,890
Gains on sales/disposals of operating property	(774)	(3,477)	(216)
Deferred income taxes, net	(17,031)	6,328	6,792
Stock-based compensation	7,721	2,747	6,925
Changes in operating assets and liabilities:
(Increase) decrease in trade and other accounts receivable	(181,235)	(6,233)	20,713
(Increase) decrease in other assets	(1,966)	9,298	(1,177)
Increase (decrease) in accounts payable	68,859	(9,598)	3,632
Increase in other liabilities	22,085	288	1,222
Increase (decrease) in insurance claims	16,056	11,770	(4,768)
NET CASH PROVIDED BY OPERATING ACTIVITIES	138,963	190,242	216,022
INVESTING ACTIVITIES
Sales and maturities of investments	56,442	41,795	38,684
Purchases of investments	(58,504)	(43,529)	(44,238)
Purchases of operating property	(15,586)	(22,645)	(4,804)
Proceeds from sales of operating property	4,032	10,212	1,685
Consideration paid for acquisitions	(8,460)
NET CASH USED BY INVESTING ACTIVITIES	(22,076)	(14,167)	(8,673)
FINANCING ACTIVITIES
Increase in cash overdraft	5,991	642	980
Dividends paid	(15,938)	(14,332)	(57,882)
Payment for debt issue costs		(1,048)
Proceeds from exercises of stock options	3,183	2,329	1,459
Taxes paid in lieu of shares issued related to stock-based compensation plans	(881)	(3,043)	(2,225)
Excess tax benefits from stock-based awards		1,386	671
Purchases of common stock	0	(50,516)	(161,152)
Principal payments on capital lease obligations	(46,751)	(47,492)	(36,520)
NET CASH USED BY FINANCING ACTIVITIES	(54,396)	(112,074)	(254,669)
Effect of exchange rate changes on cash and cash equivalents	1,028	376	(2,104)
Increase (decrease) in cash and cash equivalents	63,519	64,377	(49,424)
Cash and cash equivalents at beginning of period	178,897	114,520	163,944
Cash and cash equivalents at end of period	$ 242,416	$ 178,897	$ 114,520

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock at Cost	Accumulated Other Comprehensive (Loss) Income	Non-controlling Interests
Beginning Balance (in shares) at Dec. 27, 2014		67,268,817			22,474,331
Beginning Balance at Dec. 27, 2014	$ 488,261	$ 673	$ 189,012	$ 1,255,374	$ (955,613)	$ (1,185)
Net income (loss)	147,689			147,689
Dividends	(13,088)			(13,088)
Purchases of common stock (in shares)					2,497,748
Purchases of common stock	(161,152)				$ (161,152)
Issuance of stock related to stock-based compensation plans, including excess tax effect (in shares)		122,799
Issuance of stock related to stock-based compensation plans, including excess tax effect	(95)	$ 1	(96)
Stock-based compensation	6,925		6,925
Other comprehensive income (loss)	(2,303)					(2,303)
Ending Balance (in shares) at Dec. 26, 2015		67,391,616			24,972,079
Ending Balance at Dec. 26, 2015	466,237	$ 674	195,841	1,389,975	$ (1,116,765)	(3,488)
Net income (loss)	137,350			137,350
Dividends	(14,332)			(14,332)
Purchases of common stock (in shares)					773,281
Purchases of common stock	(50,516)				$ (50,516)
Issuance of stock related to stock-based compensation plans, including excess tax effect (in shares)		194,059			2,181
Issuance of stock related to stock-based compensation plans, including excess tax effect	672	$ 2	826		$ (156)
Stock-based compensation	2,747		2,747
Other comprehensive income (loss)	399					399
Ending Balance (in shares) at Dec. 31, 2016		67,585,675			25,747,541
Ending Balance at Dec. 31, 2016	542,557	$ 676	199,414	1,512,993	$ (1,167,437)	(3,089)
Net income (loss)	176,996			177,088			$ (92)
Dividends	(78,923)			(78,923)
Purchases of common stock (in shares)					0
Issuance of stock related to stock-based compensation plans, including excess tax effect (in shares)		154,705			1,952
Issuance of stock related to stock-based compensation plans, including excess tax effect	2,302	$ 1	2,464		$ (163)
Stock-based compensation	7,721		7,721
Other comprehensive income (loss)	(417)					(73)	(344)
Acquired business and noncontrolling interests	3,641						3,641
Ending Balance (in shares) at Dec. 30, 2017		67,740,380			25,749,493
Ending Balance at Dec. 30, 2017	$ 653,877	$ 677	$ 209,599	$ 1,611,158	$ (1,167,600)	$ (3,162)	$ 3,205

Significant Accounting Policies

12 Months Ended

Dec. 30, 2017

Significant Accounting Policies

(1) Significant Accounting Policies

Consolidation

The consolidated financial statements include the accounts of Landstar System, Inc. and its subsidiary, Landstar System Holdings, Inc. (“LSHI”). Landstar System, Inc. and its subsidiary are herein referred to as “Landstar” or the “Company.” Landstar owns, through various subsidiaries, a controlling interest in Landstar Metro, S.A.P.I. de C.V., a transportation logistics company (“Landstar Metro”), and Landstar Metro Servicios S.A.P.I. de C.V., a services company (“Landstar Servicios”), each based in Mexico City, Mexico. Given Landstar’s controlling interest in each of Landstar Metro and Landstar Servicios, the accounts of Landstar Metro and Landstar Servicios have been consolidated herein and a noncontrolling interest has been recorded for the noncontrolling investors’ interests in the net assets and operations of Landstar Metro and Landstar Servicios. Significant intercompany accounts have been eliminated in consolidation.

Estimates

The preparation of the consolidated financial statements requires the use of management’s estimates. Actual results could differ from those estimates.

Fiscal Year

Landstar’s fiscal year is the 52 or 53 week period ending the last Saturday in December.

Revenue Recognition

When providing the physical transportation of freight, the Company is the primary obligor with respect to freight delivery and assumes the related credit risk. Accordingly, transportation revenue billed to customers for the physical transportation of freight and the related direct freight expenses are recognized on a gross basis upon completion of freight delivery. The Company plans to adopt Accounting Standards Update (“ASU”) 2014-09 effective as of January 1, 2018, as further described in footnote 15. The Company anticipates that the adoption of this standard will change the timing of revenue recognition for most of its transportation business from at delivery to over the transit period as the performance obligation is completed. The Company does not expect this change to have a material impact on its results of operations, financial position or cash flows once implemented. Reinsurance premiums of the insurance segment are recognized over the period earned, which is usually on a monthly basis. Fuel surcharges billed to customers for freight hauled by independent contractors who provide truck capacity to the Company under exclusive lease arrangements (the “BCO Independent Contractors”) are excluded from revenue and paid in entirety to the BCO Independent Contractors.

Insurance Claim Costs

Landstar provides, primarily on an actuarially determined basis, for the estimated costs of cargo, property, casualty, general liability and workers’ compensation claims both reported and for claims incurred but not reported. For commercial trucking claims, Landstar retains liability up to $5,000,000 per occurrence. In addition, for commercial trucking claims exceeding its $5,000,000 per occurrence self-insured retention, the Company retains an additional $700,000 in the aggregate on any claims incurred on or after May 1, 2016 through April 30, 2017, and up to an additional $500,000 in the aggregate on any claims incurred on or after May 1, 2017 through April 30, 2018. The Company also retains liability of up to $1,000,000 for each general liability claim, up to $250,000 for each workers’ compensation claim and up to $250,000 for each cargo claim.

Tires

Tires purchased as part of trailing equipment are capitalized as part of the cost of the equipment. Replacement tires are charged to expense when placed in service.

Cash and Cash Equivalents

Included in cash and cash equivalents are all investments, except those provided for collateral, with an original maturity of 3 months or less.

Financial Instruments

The Company’s financial instruments include cash equivalents, short and long-term investments, trade and other accounts receivable, accounts payable, other accrued liabilities, current and non-current insurance claims and long-term debt plus current maturities (“Debt”). The carrying value of cash equivalents, trade and other accounts receivable, accounts payable, current insurance claims and other accrued liabilities approximates fair value as the assets and liabilities are short term in nature. Short and long-term investments are carried at fair value as further described in the “Investments” footnote below. The carrying value of non-current insurance claims approximates fair value as the Company generally has the ability to, but is not required to, settle claims in a short term. The Company’s Debt includes borrowings under the Company’s revolving credit facility, to the extent there are any, plus borrowings relating to capital lease obligations used to finance trailing equipment. The interest rates on borrowings under the revolving credit facility are typically tied to short-term LIBOR rates that adjust monthly and, as such, carrying value approximates fair value. Interest rates on borrowings under capital leases approximate the interest rates that would currently be available to the Company under similar terms and, as such, carrying value approximates fair value.

Trade and Other Receivables

The allowance for doubtful accounts for both trade and other receivables represents management’s estimate of the amount of outstanding receivables that will not be collected. Estimates are used to determine the allowance for doubtful accounts for both trade and other receivables and are generally based on specific identification, historical collection results, current economic trends and changes in payment trends. Following is a summary of the activity in the allowance for doubtful accounts for fiscal years ending December 30, 2017, December 31, 2016 and December 26, 2015 (in thousands):


	Balance at Beginning of Period		Charged to Costs and Expenses		Write-offs, Net of Recoveries			Balance at End of Period
For the Fiscal Year Ended December 30, 2017
Trade receivables	$	5,161	$	3,982	$	(3,012	)	$	6,131
Other receivables		6,549		3,450		(3,047	)		6,952
Other non-current receivables		244		7		—			251

	$	11,954	$	7,439	$	(6,059	)	$	13,334

For the Fiscal Year Ended December 31, 2016
Trade receivables	$	4,327	$	2,772	$	(1,938	)	$	5,161
Other receivables		5,555		2,963		(1,969	)		6,549
Other non-current receivables		238		—		6			244

	$	10,120	$	5,735	$	(3,901	)	$	11,954

For the Fiscal Year Ended December 26, 2015
Trade receivables	$	4,338	$	3,985	$	(3,996	)	$	4,327
Other receivables		5,103		1,897		(1,445	)		5,555
Other non-current receivables		230		8		—			238

	$	9,671	$	5,890	$	(5,441	)	$	10,120

Operating Property

Operating property is recorded at cost. Depreciation is provided on a straight-line basis over the estimated useful lives of the related assets. Buildings and improvements are being depreciated over 30 years. Trailing equipment is being depreciated over 7 to 10 years. Information technology hardware and software included in other equipment is generally being depreciated over 3 to 7 years.

Goodwill

Goodwill represents the excess of the purchase price paid over the fair value of the net assets of acquired businesses. The Company has two reporting units within the transportation logistics segment that report goodwill. The Company reviews its goodwill balance annually for impairment for each reporting unit, unless circumstances dictate more frequent assessments, and in accordance with ASU 2011-08, Testing Goodwill for Impairment. ASU 2011-08 permits an initial assessment, commonly referred to as “step zero”, of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount and also provides a basis for determining whether it is necessary to perform the two-step goodwill impairment test required by ASC Topic 350. In the fourth quarter of 2017, the Company performed the qualitative assessment of goodwill and determined it was more likely than not that the fair value of each of its reporting units would be greater than its carrying amount. Therefore, the Company determined it was not necessary to perform the two-step goodwill impairment test. Furthermore, there has been no historical impairment of the Company’s goodwill.

Income Taxes

Income tax expense is equal to the current year’s liability for income taxes and a provision for deferred income taxes. Deferred tax assets and liabilities are recorded for the future tax effects attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using the enacted tax rates expected to be applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act (the “Tax Reform Act”). Further information on the tax impacts of the Tax Reform Act is included in Note 5 of the Company’s consolidated financial statements.

Share-Based Payments

The Company’s share-based payment arrangements include restricted stock units (“RSU”), stock options, non-vested restricted stock and Deferred Stock Units. The fair value of an RSU with a performance condition is determined based on the market value of the Company’s Common Stock on the date of grant, discounted for lack of marketability for a minimum post-vesting holding requirement. With respect to RSU awards with a performance condition, the Company reports compensation expense over the life of the award based on an estimated number of units that will vest over the life of the award, multiplied by the fair value of an RSU. The fair value of an RSU with a market condition is determined at the time of grant based on the expected achievement of the market condition at the end of each vesting period. With respect to RSU awards with a market condition, the Company recognizes compensation expense ratably over the requisite service period under an award based on the fair market value of the award at the time of grant, regardless of whether the market condition is satisfied. Previously recognized compensation cost would be reversed, however, if the employee terminated employment prior to completing such requisite service period. The Company estimates the fair value of stock option awards on the date of grant using the Black-Scholes pricing model and recognizes compensation cost for stock option awards expected to vest on a straight-line basis over the requisite service period for the entire award. Forfeitures are estimated at grant date based on historical experience and anticipated employee turnover. The fair values of each share of non-vested restricted stock issued and Deferred Stock Unit granted are based on the fair value of a share of the Company’s common stock on the date of grant and compensation costs for non-vested restricted stock and Deferred Stock Units are recognized on a straight-line basis over the requisite service period for the award.

Earnings Per Share

Earnings per common share attributable to Landstar System, Inc. and subsidiary are based on the weighted average number of shares outstanding, including outstanding non-vested restricted stock and outstanding Deferred Stock Units. Diluted earnings per share attributable to Landstar System, Inc. and subsidiary are based on the weighted average number of common shares and Deferred Stock Units outstanding plus the incremental shares that would have been outstanding upon the assumed exercise of all dilutive stock options.

The following table provides a reconciliation of the average number of common shares outstanding used to calculate earnings per common share attributable to Landstar System, Inc. and subsidiary to the average number of common shares and common share equivalents outstanding used to calculate diluted earnings per share attributable to Landstar System, Inc. and subsidiary (in thousands):


	Fiscal Years
	2017		2016		2015
Average number of common shares outstanding		41,938		42,112		43,664
Incremental shares from assumed exercises of stock options		86		124		149

Average number of common shares and common share equivalents outstanding		42,024		42,236		43,813

For the fiscal years ended December 30, 2017, December 31, 2016 and December 26, 2015, no options outstanding to purchase shares of Common Stock were antidilutive. Outstanding RSUs were excluded from the calculation of diluted earnings per share attributable to Landstar System, Inc. and subsidiary for all periods because the performance metric requirements or market condition for vesting had not been satisfied.

Dividends Payable

On December 11, 2017, the Company announced that its Board of Directors declared a special cash dividend of $1.50 per share payable on January 26, 2018, to stockholders of record of its Common Stock as of January 12, 2018. Dividends payable of $62,985,000 related to this special dividend were included in current liabilities in the consolidated balance sheet at December 30, 2017.

Foreign Currency Translation

Assets and liabilities of the Company’s Canadian and Mexican operations are translated from their functional currency to U.S. dollars using exchange rates in effect at the balance sheet date and revenue and expense accounts are translated at average monthly exchange rates during the period. Adjustments resulting from the translation process are included in accumulated other comprehensive income. Transactional gains and losses arising from receivable and payable balances, including intercompany balances, in the normal course of business that are denominated in a currency other than the functional currency of the operation are recorded in the statements of income when they occur.

Acquired Business and Noncontrolling Interests

12 Months Ended

Dec. 30, 2017

Acquired Business and Noncontrolling Interests

(2) Acquired Business and Noncontrolling Interests

During 2017, the Company incorporated each of Landstar Metro and Landstar Servicios. On September 20, 2017, Landstar Metro acquired substantially all of the assets of the asset-light transportation logistics business of Fletes Avella, S.A. de C.V., a Mexican transportation logistics company. Cash consideration paid in fiscal year 2017 for the acquisition was approximately $8,460,000. In addition, at December 30, 2017, there was approximately $1,900,000 in liabilities outstanding consisting of additional contingent purchase price and associated indirect taxes. In connection with the acquisition, individuals affiliated with the seller subscribed in the aggregate for a 30% equity interest in each of Landstar Metro and Landstar Servicios. The asset acquisition by Landstar Metro was accounted for as a business combination in accordance with Accounting Standards Codification 805, Business Combinations (“ASC 805”). The resulting goodwill arising from the acquisition was approximately $8,800,000. With respect to this goodwill, 70% is expected to be deductible by the Company for U.S. income tax purposes, and following the purchase of the noncontrolling interests by the Company, up to 100% of this goodwill would be expected to be deductible by the Company. Pro forma financial information for prior periods is not presented as the Company does not believe the acquisition to be material to our consolidated results. The results of operations from Landstar Metro and Landstar Servicios are presented as part of the Company’s transportations logistics segment. During the fiscal year ended December 30, 2017, the Company incurred approximately $1,000,000, or $0.01 per common share ($0.01 per diluted share), in one-time costs related to the completion of the acquisition and subscription of the non-controlling interests.

As it relates to the noncontrolling interests of Landstar Metro and Landstar Servicios, the Company has the option to purchase, and the minority equityholders have the option to sell, during the period commencing on the third anniversary of September 20, 2017, the closing date of the subscription by the minority equityholders (the “Closing Date”), and at any time after the fourth anniversary of the Closing Date, at fair value all but not less than all of the noncontrolling interests in Landstar Metro and Landstar Servicios. The noncontrolling interests are also subject to customary restrictions on transfer, including a right of first refusal in favor of the Company.

Other Comprehensive Income

12 Months Ended

Dec. 30, 2017

Other Comprehensive Income

(3) Other Comprehensive Income

The following table presents the components of and changes in accumulated other comprehensive income attributable to Landstar System, Inc. and subsidiary, net of related income taxes, as of and for the fiscal years ended December 30, 2017, December 31, 2016 and December 26, 2015 (in thousands):


	Unrealized Holding Gains (Losses) on Available-for-Sale Securities			Foreign Currency Translation			Total
Balance as of December 27, 2014	$	105		$	(1,290	)	$	(1,185	)
Other comprehensive loss		(199	)		(2,104	)		(2,303	)

Balance as of December 26, 2015		(94	)		(3,394	)		(3,488	)
Other comprehensive income		23			376			399

Balance as of December 31, 2016		(71	)		(3,018	)		(3,089	)
Other comprehensive loss		(73	)		—			(73	)

Balance as of December 30, 2017	$	(144	)	$	(3,018	)	$	(3,162	)

Amounts reclassified from accumulated other comprehensive income to investment income due to the realization of previously unrealized gains and losses in the accompanying consolidated statements of income were not significant for the fiscal years ended December 30, 2017, December 31, 2016 and December 26, 2015.

Investments

12 Months Ended

Dec. 30, 2017

Investments

(4) Investments

Investments include primarily investment-grade corporate bonds, money market investments and U.S. Treasury obligations having maturities of up to five years (the “bond portfolio”). Investments in the bond portfolio are reported as available-for-sale and are carried at fair value. Investments maturing less than one year from the balance sheet date are included in short-term investments and investments maturing more than one year from the balance sheet date are included in other assets in the consolidated balance sheets. Management performs an analysis of the nature of the unrealized losses on available-for-sale investments to determine whether such losses are other-than-temporary. Unrealized losses, representing the excess of the purchase price of an investment over its fair value as of the end of a period, considered to be other-than-temporary, are to be included as a charge in the statement of income, while unrealized losses considered to be temporary are to be included as a component of equity. Investments whose values are based on quoted market prices in active markets are classified within Level 1. Investments that trade in markets that are not considered to be active, but are valued based on quoted market prices, are classified within Level 2. As Level 2 investments include positions that are not traded in active markets, valuations may be adjusted to reflect illiquidity and/or non-transferability, which are generally based on available market information. Any transfers between levels are recognized as of the beginning of any reporting period. Fair value of the bond portfolio was determined using Level 1 inputs related to U.S. Treasury obligations and money market investments and Level 2 inputs related to investment-grade corporate bonds, asset-backed securities and direct obligations of government agencies. Unrealized losses, net of unrealized gains, on the investments in the bond portfolio were $223,000 and $109,000 at December 30, 2017 and December 31, 2016, respectively.

The amortized cost and fair values of available-for-sale investments are as follows at December 30, 2017 and December 31, 2016 (in thousands):


			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
December 30, 2017
Money market investments	$	27,895	$	—	$	—	$	27,895
Asset-backed securities		2,805		—		5		2,800
Corporate bonds and direct obligations of government agencies		80,442		117		335		80,224

Total	$	111,142	$	117	$	340	$	110,919

December 31, 2016
Money market investments	$	12,395	$	—	$	—	$	12,395
Asset-backed securities		4,027		3		19		4,011
Corporate bonds and direct obligations of government agencies		70,069		150		239		69,980
U.S. Treasury obligations		23,037		2		6		23,033

Total	$	109,528	$	155	$	264	$	109,419

For those available-for-sale investments with unrealized losses at December 30, 2017 and December 31, 2016, the following table summarizes the duration of the unrealized loss (in thousands):


	Less than 12 months				12 months or longer				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
December 30, 2017
Asset-backed securities	$	1,864	$	4	$	632	$	1	$	2,496	$	5
Corporate bonds and direct obligations of government agencies		41,322		220		14,016		115		55,338		335

Total	$	43,186	$	224	$	14,648	$	116	$	57,834	$	340

December 31, 2016
Asset-backed securities	$	1,363	$	6	$	2,314	$	13	$	3,677	$	19
Corporate bonds and direct obligations of government agencies		28,809		195		1,367		44		30,176		239
U.S. Treasury obligations		12,734		6		—		—		12,734		6

Total	$	42,906	$	207	$	3,681	$	57	$	46,587	$	264

The Company believes that unrealized losses on investments were primarily caused by rising interest rates rather than changes in credit quality. The Company expects to recover the amortized cost basis of these securities as it does not intend to sell, and does not anticipate being required to sell, these securities before recovery of the cost basis. For these reasons, the Company does not consider the unrealized losses on these securities to be other-than-temporary at December 30, 2017.

Short-term investments include $48,928,000 in current maturities of investments held by the Company’s insurance segment at December 30, 2017. The non-current portion of the bond portfolio of $61,991,000 is included in other assets. The short-term investments, together with $17,112,000 of non-current investments, provide collateral for the $59,436,000 of letters of credit issued to guarantee payment of insurance claims.

Investment income represents the earnings on the insurance segment’s assets. Investment income earned from the assets of the insurance segment are included as a component of operating income as the investment of these assets is critical to providing collateral, liquidity and earnings with respect to the operation of the Company’s insurance programs.

Income Taxes

12 Months Ended

Dec. 30, 2017

Income Taxes

(5) Income Taxes

The provisions for income taxes consisted of the following (in thousands):


	Fiscal Years
	2017			2016		2015
Current:
Federal	$	72,025		$	68,548	$	74,289
State		8,312			6,668		9,550
Foreign		500			563		437

Total current	$	80,837		$	75,779	$	84,276

Deferred:
Federal	$	(17,110	)	$	6,104	$	6,524
State		79			224		268

Total deferred	$	(17,031	)	$	6,328	$	6,792

Income taxes	$	63,806		$	82,107	$	91,068

On December 22, 2017, the President of the United States signed into law the Tax Reform Act. The legislation significantly changed U.S. tax law by, among other things, lowering corporate income tax rates, implementing a territorial tax system and imposing a repatriation tax on deemed repatriated earnings of foreign subsidiaries. With respect to the change in corporate tax rates, the Tax Reform Act permanently reduced the U.S. corporate income tax rate from a maximum of 35% to a flat 21% rate, effective January 1, 2018. In connection with this reduction in the U.S. corporate income tax rate, the Company revalued its ending net deferred tax liabilities at December 30, 2017 resulting in a provisional $20,430,000 tax benefit in the Company’s consolidated statement of income for the year ended December 30, 2017. With respect to the repatriation tax on deemed repatriated earnings of foreign subsidiaries, the Tax Reform Act provided for a one-time deemed mandatory repatriation of post-1986 undistributed foreign subsidiary earnings and profits (“E&P”) through the year ended December 31, 2017. The Company had an estimated $17,981,000 of undistributed foreign E&P at the Company’s Canadian subsidiary, Landstar Canada, Inc. subject to the deemed mandatory repatriation and, accordingly, recognized a provisional $900,000 of income tax expense in the Company’s consolidated statement of income for the year ended December 30, 2017. After the utilization of existing tax credits, the Company expects to pay U.S. federal cash taxes of approximately $500,000 on the deemed mandatory repatriation, payable over eight years.

On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. The Company has recognized the provisional tax impacts related to deemed repatriated earnings and the revaluation of deferred tax assets and liabilities and included these amounts in its consolidated financial statements for the year ended December 30, 2017. The ultimate impact may differ from these provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the Tax Reform Act. The accounting is expected to be complete when the 2017 U.S. corporate income tax return is filed in 2018.

Also during fiscal year 2017, the Company adopted ASU 2016-09, as further described in footnote 15. As required by ASU 2016-09, the Company recognized $1,299,000 of excess tax benefits on stock-based awards in its provision for income taxes in the 2017 fiscal year.

Temporary differences and carryforwards which gave rise to deferred tax assets and liabilities consisted of the following (in thousands):


	Dec. 30, 2017		Dec. 31, 2016
Deferred tax assets:
Receivable valuations	$	3,244	$	4,518
Share-based payments		2,182		1,185
Self-insured claims		4,688		6,270
Other		3,666		4,336

Total deferred tax assets	$	13,780	$	16,309

Deferred tax liabilities:
Operating property	$	43,105	$	59,720
Goodwill		3,773		5,883
Other		2,016		2,851

Total deferred tax liabilities	$	48,894	$	68,454

Net deferred tax liability	$	35,114	$	52,145

The following table summarizes the differences between income taxes calculated at the federal income tax rate of 35% on income before income taxes and the provisions for income taxes (in thousands):


	Fiscal Years
	2017			2016			2015
Income taxes at federal income tax rate	$	84,281		$	76,810		$	83,565
State income taxes, net of federal income tax benefit		5,417			4,505			7,201
Meals and entertainment exclusion		1,021			958			946
Share-based payments		(1,549	)		(239	)		(61	)
Section 199 deductions and R&D credits		(5,546	)		(250	)		—
Tax Reform Act		(19,530	)		—			—
Other, net		(288	)		323			(583	)

Income taxes	$	63,806		$	82,107		$	91,068

The Company files a consolidated U.S. federal income tax return. The Company or its subsidiaries file state tax returns in the majority of the U.S. state tax jurisdictions. With few exceptions, the Company and its subsidiaries are no longer subject to U.S. federal or state income tax examinations by tax authorities for 2013 and prior years. The Company’s wholly owned Canadian subsidiary, Landstar Canada, Inc., is subject to Canadian income and other taxes. The Company’s wholly owned Mexican subsidiary, Landstar Holdings, S. de R.L.C.V. and 70% owned subsidiaries, Landstar Metro, S.A.P.I. de C.V. and Landstar Metro Servicios S.A.P.I. de C.V. are subject to Mexican and U.S. income and other taxes.

As of December 30, 2017 and December 31, 2016, the Company had $3,670,000 and $1,829,000, respectively, of net unrecognized tax benefits representing the provision for the uncertainty of certain tax positions plus a component of interest and penalties. Estimated interest and penalties on the provision for the uncertainty of certain tax positions is included in income tax expense. At December 30, 2017 and December 31, 2016 there was $627,000 and $547,000, respectively, accrued for estimated interest and penalties related to the uncertainty of certain tax positions. The Company does not currently anticipate any significant increase or decrease to the unrecognized tax benefit during fiscal year 2018.

The following table summarizes the rollforward of the total amounts of gross unrecognized tax benefits for fiscal years 2017 and 2016 (in thousands):


	Fiscal Years
	2017			2016
Gross unrecognized tax benefits – beginning of the year	$	2,635		$	2,704
Gross increases related to current year tax positions		645			428
Gross increases related to prior year tax positions		2,189			596
Gross decreases related to prior year tax positions		(75	)		(399	)
Settlements		(100	)		(133	)
Lapse of statute of limitations		(482	)		(561	)

Gross unrecognized tax benefits – end of the year	$	4,812		$	2,635

Landstar paid income taxes of $86,607,000 in fiscal year 2017, $69,067,000 in fiscal year 2016 and $74,619,000 in fiscal year 2015.

Operating Property

12 Months Ended

Dec. 30, 2017

Operating Property

(6) Operating Property

Operating property is summarized as follows (in thousands):


	Dec. 30, 2017		Dec. 31, 2016
Land	$	15,259	$	15,259
Buildings and improvements		57,758		56,413
Trailing equipment		363,377		342,813
Other equipment		58,317		48,732

Total operating property, gross		494,711		463,217
Less accumulated depreciation and amortization		218,700		190,374

Total operating property, net	$	276,011	$	272,843

Included above is $239,438,000 in fiscal year 2017 and $249,717,000 in fiscal year 2016 of operating property under capital leases, $171,658,000 and $183,763,000, respectively, net of accumulated depreciation and amortization. Landstar acquired operating property by entering into capital leases in the amount of $33,560,000 in fiscal year 2017, $61,504,000 in fiscal year 2016 and $49,491,000 in fiscal year 2015.

Debt

12 Months Ended

Dec. 30, 2017

Debt

(8) Debt

Other than the capital lease obligations as presented on the consolidated balance sheets, the Company had no outstanding debt as of December 30, 2017 and December 31, 2016.

On June 2, 2016, Landstar entered into a credit agreement with a syndicate of banks and JPMorgan Chase Bank, N.A., as administrative agent (the “Credit Agreement”). The Credit Agreement, which matures on June 2, 2021, provides $250,000,000 of borrowing capacity in the form of a revolving credit facility, $50,000,000 of which may be utilized in the form of letter of credit guarantees. The Credit Agreement includes an “accordion” feature providing for a possible increase up to an aggregate borrowing amount of $400,000,000. The Company’s prior credit agreement was terminated on June 2, 2016. Borrowings under the Credit Agreement are unsecured, however, all but four of the Company’s U.S. subsidiaries guarantee the obligations under the Credit Agreement along with Signature Insurance Company. On February 2, 2018, Landstar entered into an amendment to the Credit Agreement whereby Landstar Canada Holdings, Inc., the U.S. parent of Landstar Canada, and Landstar MH I, LL, the U.S. parent of Landstar Holdings, S. de R.L.C.V., Landstar Metro and Landstar Servicios, in lieu of providing a guarantee of the obligations under the Credit Agreement, granted to the administrative agent, for the benefit of the bank syndicate, a first-priority, perfected pledge and security interest in 65% of each series of its outstanding voting capital stock and 100% of each series of its outstanding non-voting capital stock. Any future amounts that may become outstanding under the Credit Agreement are payable on June 2, 2021, the maturity date of the Credit Agreement.

Depending upon the specific type of borrowing, borrowings under the Credit Agreement bear interest based on either (a) the prime rate, (b) the Federal Reserve Bank of New York rate plus 0.5% or (c) the London Interbank Offered Rate, plus 1.25%. The unused portion of the revolving credit facility under the Credit Agreement carries a commitment fee determined based on the level of the Leverage Ratio. The commitment fee for the unused portion of the revolving credit facility under the Credit Agreement ranges from .15% to .25%, based on achieving certain levels of the Leverage Ratio. As of December 30, 2017 and December 31, 2016, the Company had no borrowings outstanding under the Credit Agreement.

The Credit Agreement contains a number of covenants that limit, among other things, the incurrence of additional indebtedness. The Company is required to, among other things, maintain a minimum Fixed Charge Coverage Ratio, as defined in the Credit Agreement, and maintain a Leverage Ratio, as defined in the Credit Agreement, below a specified maximum. The Credit Agreement provides for a restriction on cash dividends and other distributions to stockholders on the Company’s capital stock to the extent there is a default under the Credit Agreement. In addition, the Credit Agreement under certain circumstances limits the amount of such cash dividends and other distributions to stockholders to the extent that, after giving effect to any payment made to effect such cash dividend or other distribution, the Leverage Ratio would exceed 2.5 to 1 on a pro forma basis as of the end of the Company’s most recently completed fiscal quarter. The Credit Agreement provides for an event of default in the event that, among other things, a person or group acquires 35% or more of the outstanding capital stock of the Company or obtains power to elect a majority of the Company’s directors or the directors cease to consist of a majority of Continuing Directors, as defined in the Credit Agreement. None of these covenants are presently considered by management to be materially restrictive to the Company’s operations, capital resources or liquidity. The Company is currently in compliance with all of the debt covenants under the Credit Agreement.

The interest rates on borrowings under the revolving credit facility are typically tied to short-term LIBOR rates that adjust monthly and, as such, carrying value approximates fair value. Interest rates on borrowings under capital leases approximate the interest rates that would currently be available to the Company under similar terms and, as such, carrying value approximates fair value.

Landstar paid interest of $3,891,000 in fiscal year 2017, $3,794,000 in fiscal year 2016 and $3,012,000 in fiscal year 2015.

Leases

12 Months Ended

Dec. 30, 2017

Leases

(9) Leases

The future minimum lease payments under all noncancelable leases at December 30, 2017, principally for trailing equipment, are shown in the following table (in thousands):


	Capital Leases		Operating Leases
2018	$	44,810	$	302
2019		36,632		180
2020		29,261		5
2021		14,799		—
2022		5,588		—
Thereafter		—		—

Total future minimum lease payments		131,090	$	487

Less amount representing interest (2.0% to 3.5%)		5,977

Present value of minimum lease payments	$	125,113

Total rent expense/income, net of sublease income, was $1,419,000 income in fiscal year 2017, $1,641,000 income in fiscal year 2016 and $318,000 expense in fiscal year 2015.

Share-Based Payment Arrangements

12 Months Ended

Dec. 30, 2017

Share-Based Payment Arrangements

(10) Share-Based Payment Arrangements

As of December 30, 2017, the Company had two employee equity incentive plans, the 2002 employee stock option and stock incentive plan (the “ESOSIP”) and the 2011 equity incentive plan (the “2011 EIP”). No further grants can be made under the ESOSIP. The Company also has a stock compensation plan for members of its Board of Directors, the Amended and Restated 2013 Directors Stock Compensation Plan (as amended and restated as of May 17, 2016, the “2013 DSCP”). 6,000,000 shares of the Company’s Common Stock were authorized for issuance under the 2011 EIP and 115,000 shares of the Company’s Common Stock were authorized for issuance under the 2013 DSCP. The ESOSIP, 2011 EIP and 2013 DSCP are each referred to herein as a “Plan,” and, collectively, as the “Plans.” Amounts recognized in the financial statements with respect to these Plans are as follows (in thousands):


	Fiscal Years
	2017			2016			2015
Total cost of the Plans during the period	$	7,721		$	2,747		$	6,925
Amount of related income tax benefit recognized during the period		(3,285	)		(1,238	)		(2,432	)

Net cost of the Plans during the period	$	4,436		$	1,509		$	4,493

Included in income tax benefits recognized in the fiscal years ended December 30, 2017 and December 31, 2016 were income tax benefits of $339,000 and $451,000, respectively, recognized on disqualifying dispositions of the Company’s Common Stock by employees who obtained shares of Common Stock through exercises of incentive stock options. Also included in income tax benefits recognized in the fiscal year ended December 30, 2017 were excess tax benefits from stock-based awards of $1,299,000, as required by the Company’s adoption of Accounting Standards Update 2016-09 during the first fiscal quarter of 2017. See Note 15, Recent Accounting Pronouncements, for further information.

As of December 30, 2017, there were 78,682 shares of the Company’s Common Stock reserved for issuance under the 2013 DSCP and 4,678,411 shares of the Company’s Common Stock reserved for issuance in the aggregate under the ESOSIP and 2011 EIP.

Restricted Stock Units

The following table summarizes information regarding the Company’s outstanding restricted stock unit (“RSU”) awards with either a performance condition or a market condition under the Plans:


	Number of			Weighted Average Grant Date
	RSUs			Fair Value
Outstanding at December 27, 2014		425,630		$	50.72
Granted		111,922		$	53.30
Vested		(91,382	)	$	51.98
Forfeited		(2,013	)	$	52.81

Outstanding at December 26, 2015		444,157		$	51.10
Granted		79,948		$	51.58
Vested		(81,344	)	$	53.08
Forfeited		(64,523	)	$	52.99

Outstanding at December 31, 2016		378,238		$	50.46
Granted		67,913		$	76.81
Forfeited		(58,779	)	$	46.00

Outstanding at December 30, 2017		387,372		$	55.75

During fiscal years 2015, 2016 and 2017 the Company granted RSUs with a performance condition. During fiscal year 2015, the Company also issued RSUs with a market condition, as further described below.

RSUs with a performance condition granted on February 2, 2017 may vest on January 31 of 2020, 2021 and 2022. RSUs with a performance condition granted on January 29, 2016 may vest on January 31 of 2019, 2020 and 2021. RSUs with a performance condition granted on January 27, 2015 may vest on January 31 of 2018, 2019 and 2020. RSUs with a performance condition vest based on growth in operating income and diluted earnings per share from continuing operations attributable to Landstar System Inc. and subsidiary as compared to a base year, being the year immediately preceding the year of grant. At the time of grant, the target number of common shares available for issuance under the February 2, 2017, January 29, 2016 and January 27, 2015 grants equals 100% of the number of RSUs granted, and the maximum number of common shares available for issuance under the February 2, 2017, January 29, 2016 and January 27, 2015 grants equals 200% of the number of RSUs granted. In the event actual results exceed the target, the number of shares that will be granted will exceed the number of RSUs granted. The maximum number of common shares available for issuance under grants made prior to 2015 equals 100% of the number of RSUs granted. The fair value of an RSU with a performance condition was determined based on the market value of the Company’s Common Stock on the date of grant, discounted for lack of marketability for a minimum post-vesting holding requirement. The discount rate due to lack of marketability used for RSU award grants with a performance condition for all periods was 7%. With respect to RSU awards with a performance condition, the Company reports compensation expense over the life of the award based on an estimated number of units that will vest over the life of the award, multiplied by the fair value of an RSU.

On May 1, 2015, the Company granted 20,000 RSUs that vest based on a market condition. These RSUs may vest on April 30 of 2019, 2020 and 2021 based on the Company’s total shareholder return (“TSR”) compound annual growth rate over the vesting periods, adjusted to reflect dividends (if any) paid during such periods and capital adjustments as may be necessary. The target number of common shares available for issuance under the May 1, 2015 grant equals 100% of the number of RSUs granted, and the maximum number of common shares available for issuance under the May 1, 2015 grant equals 150% of the number of RSUs granted. In the event actual results exceed the target TSR compound annual growth rate, the number of shares that will be granted will exceed the number of RSUs granted. The fair value of this RSU award was determined at the time of grant based on the expected achievement of the market condition at the end of each vesting period. With respect to these RSU awards with a market condition, compensation expense is recognized ratably over the requisite service period under an award based on the fair market value of the award at the time of grant, regardless of whether the market condition is satisfied. Previously recognized compensation cost would be reversed, however, if the employee terminated employment prior to completing such requisite service period.

The Company recognized approximately $5,849,000, $849,000 and $4,943,000 of share-based compensation expense related to RSU awards in fiscal years 2017, 2016 and 2015, respectively. As of December 30, 2017, there was a maximum of $28.4 million of total unrecognized compensation cost related to RSU awards granted under the Plans with an expected average remaining life of approximately 2.6 years. Included in the $28.4 million of total unrecognized compensation cost is $3.4 million of unrecognized compensation cost related to 68,592 unvested units granted in 2013, which forfeited during the first fiscal quarter of 2018.With respect to RSU awards with a performance condition, the amount of future compensation expense to be recognized will be determined based on future operating results.

Stock Options

The Company did not grant any stock options during its 2015, 2016 or 2017 fiscal years. Options outstanding under the Plans generally become exercisable in either five equal annual installments commencing on the first anniversary of the date of grant or 100% on the fifth anniversary from the date of grant, subject to acceleration in certain circumstances. All options granted under the Plans expire on the tenth anniversary of the date of grant. Under the Plans, the exercise price of each option equals the fair market value of the Company’s Common Stock on the date of grant.

The fair value of each option grant on its grant date was calculated using the Black-Scholes option pricing model. The Company utilizes historical data, including exercise patterns and employee departure behavior, in estimating the term that options will be outstanding. Expected volatility was based on historical volatility and other factors, such as expected changes in volatility arising from planned changes to the Company’s business, if any. The risk-free interest rate was based on the yield of zero coupon U.S. Treasury bonds for terms that approximated the terms of the options granted.

The following table summarizes information regarding the Company’s outstanding stock options under the Plans:


	Options Outstanding					Options Exercisable
	Number of Options			Weighted Average Exercise Price per Share		Number of Options		Weighted Average Exercise Price per Share
Options at December 27, 2014		773,839		$	46.92		379,389	$	44.61
Exercised		(133,518	)	$	45.25
Forfeited		(3,100	)	$	52.91

Options at December 26, 2015		637,221		$	47.24		415,121	$	45.12
Exercised		(257,460	)	$	45.63
Forfeited		(7,200	)	$	53.63

Options at December 31, 2016		372,561		$	48.24		282,461	$	46.39
Exercised		(180,321	)	$	47.01
Forfeited		(3,200	)	$	52.47

Options at December 30, 2017		189,040		$	49.34		169,240	$	48.50

The following tables summarize stock options outstanding and exercisable at December 30, 2017:


	Options Outstanding
Range of Exercise Prices Per Share	Number Outstanding		Weighted Average Remaining Contractual Term (years)		Weighted Average Exercise Price per Share
$35.64 - $40.00		15,400		1.6	$	36.46
$40.01 - $45.00		49,250		3.1	$	41.76
$45.01 - $58.06		124,390		4.5	$	53.93

		189,040		3.9	$	49.34


	Options Exercisable
Range of Exercise Prices Per Share	Number Exercisable		Weighted Average Remaining Contractual Term (years)		Weighted Average Exercise Price per Share
$35.64 - $40.00		15,400		1.6	$	36.46
$40.01 - $45.00		49,250		3.1	$	41.76
$45.01 - $56.40		104,590		4.4	$	53.45

		169,240		3.8	$	48.50

At December 30, 2017, the total intrinsic value of options outstanding was $10,352,000. At December 30, 2017, the total intrinsic value of options outstanding and exercisable was $9,410,000. The total intrinsic value of stock options exercised during fiscal years 2017, 2016 and 2015 was $7,599,000, $7,427,000 and $2,954,000, respectively.

As of December 30, 2017, there was $29,000 of total unrecognized compensation cost related to non-vested stock options granted under the Plans. The unrecognized compensation cost related to these non-vested options is expected to be recognized during 2018.

Non-vested Restricted Stock and Deferred Stock Units

The 2011 EIP provides the Compensation Committee of the Board of Directors with the authority to issue shares of Common Stock of the Company, subject to certain vesting and other restrictions on transfer (“restricted stock”).

The following table summarizes information regarding the Company’s outstanding shares of non-vested restricted stock and Deferred Stock Units (defined below) under the Plans:


	Number of Shares and Deferred Stock Units			Weighted Average Grant Date Fair Value
Outstanding at December 27, 2014		23,353		$	54.90
Granted		1,197		$	62.46
Vested		(6,490	)	$	57.79

Outstanding at December 26, 2015		18,060		$	54.36
Granted		26,033		$	58.53
Vested		(15,684	)	$	53.03

Outstanding at December 31, 2016		28,409		$	58.91
Granted		42,573		$	84.47
Vested		(16,227	)	$	61.50

Outstanding at December 30, 2017		54,755		$	78.02

The fair value of each share of non-vested restricted stock issued and Deferred Stock Unit granted under the Plans are based on the fair value of a share of the Company’s Common Stock on the date of grant. Shares of non-vested restricted stock are generally subject to vesting in three equal annual installments either on the first, second and third anniversary of the date of grant or the third, fourth and fifth anniversary of the date of the grant, or 100% on the first anniversary of the date of the grant. For restricted stock awards granted under the 2013 DSCP plan, each recipient may elect to defer receipt of shares and instead receive restricted stock units (“Deferred Stock Units”), which represent contingent rights to receive shares of the Company’s Common Stock on the date of recipient separation from service from the Board of Directors, or, if earlier, upon a change in control event of the Company. Deferred Stock Units become vested 100% on the first anniversary of the date of the grant. Deferred Stock Units do not represent actual ownership in shares of the Company’s Common Stock and the recipient will not have voting rights or other incidents of ownership until the shares are issued. However, Deferred Stock Units do contain the right to receive dividend equivalent payments prior to settlement into shares.

As of December 30, 2017, there was $2,967,000 of total unrecognized compensation cost related to non-vested shares of restricted stock and Deferred Stock Units granted under the Plans. The unrecognized compensation cost related to these non-vested shares of restricted stock and Deferred Stock Units is expected to be recognized over a weighted average period of 2.9 years.

Directors’ Stock Compensation Plan

Commencing as of the 2016 annual meeting of the stockholders of the Company (an “Annual Meeting”), Directors of the Company who are not employees of the Company (each an “Eligible Director”) are entitled under the 2013 DSCP to receive a grant of such number of restricted shares of the Company’s Common Stock or Deferred Stock Units equal to the quotient of $110,000 divided by the fair market value of a share of Common Stock on the date immediately following the date of each Annual Meeting. With respect to the 2016 Annual Meeting only, each Eligible Director who was designated as a Class III director instead received a number of shares equal to the quotient of $35,000 divided by the fair market value of a share of Common Stock. Prior to the 2016 Annual Meeting, upon election or re-election to the Board of Directors for a three year term, Eligible Directors received a grant of such number of restricted shares of the Company’s Common Stock equal to the quotient of $225,000 divided by the fair market value of a share of Common Stock on the date immediately following the date of such Eligible Director’s re-election or election to the Board. In fiscal year 2017, 6,575 restricted shares and 1,315 Deferred Stock Units were granted to Eligible Directors. In fiscal years 2016 and 2015, 7,762 restricted shares and 1,197 restricted shares, respectively, were granted to Eligible Directors. Restricted shares and Deferred Stock Units granted in 2016 and 2017 vest on the date of the next Annual Meeting. Restricted shares granted prior to 2016 generally vest in three equal annual installments on the first three annual anniversary dates of the date of grant. During fiscal years 2017, 2016 and 2015, $651,000, $591,000 and $419,000, respectively, of compensation cost was recorded for the grant of these restricted shares and Deferred Stock Units.

Equity

12 Months Ended

Dec. 30, 2017

Equity

(11) Equity

On May 19, 2015, the Landstar System, Inc. Board of Directors authorized the Company to increase the number of shares of the Company’s Common Stock that the Company is authorized to purchase from time to time in the open market and in privately negotiated transactions under a previously announced purchase program to 3,000,000 shares. On December 11, 2017, the Landstar System, Inc. Board of Directors authorized the Company to purchase up to 1,963,875 shares of the Company’s Common Stock from time to time in the open market and in privately negotiated transactions. As of December 30, 2017, the Company has authorization to purchase 3,000,000 shares of its Common Stock in the aggregate under these programs. No specific expiration date has been assigned to either the May 19, 2015 or December 11, 2017 authorizations. During fiscal year 2017, Landstar did not purchase any shares of its Common Stock.

The Company has 2,000,000 shares of preferred stock authorized and unissued.

Commitments and Contingencies

12 Months Ended

Dec. 30, 2017

Commitments and Contingencies

(12) Commitments and Contingencies

At December 30, 2017, in addition to the $59,436,000 letters of credit secured by investments, Landstar had $33,124,000 of letters of credit outstanding under the Credit Agreement.

The Company is involved in certain claims and pending litigation arising from the normal conduct of business. Many of these claims are covered in whole or in part by insurance. Based on knowledge of the facts and, in certain cases, opinions of outside counsel, management believes that adequate provisions have been made for probable losses with respect to the resolution of all such claims and pending litigation and that the ultimate outcome, after provisions therefor, will not have a material adverse effect on the financial condition of the Company, but could have a material effect on the results of operations in a given quarter or year.

Segment Information

12 Months Ended

Dec. 30, 2017

Segment Information

(13) Segment Information

Landstar markets its integrated transportation management solutions primarily through independent commission sales agents and exclusively utilizes third party capacity providers to transport customers’ freight. Landstar’s independent commission sales agents enter into contractual arrangements with the Company and are responsible for locating freight, making that freight available to Landstar’s capacity providers and coordinating the transportation of the freight with customers and capacity providers. The Company’s third party capacity providers consist of independent contractors who provide truck capacity to the Company under exclusive lease arrangements (the “BCO Independent Contractors”), unrelated trucking companies who provide truck capacity to the Company under non-exclusive contractual arrangements (the “Truck Brokerage Carriers”), air cargo carriers, ocean cargo carriers and railroads. Through this network of agents and capacity providers linked together by Landstar’s information technology systems, Landstar operates an integrated transportation management solutions business primarily throughout North America with revenue of $3.6 billion during the most recently completed fiscal year. The Company reports the results of two operating segments: the transportation logistics segment and the insurance segment.

The transportation logistics segment provides a wide range of integrated transportation management solutions. Transportation services offered by the Company include truckload and less-than-truckload transportation, rail intermodal, air cargo, ocean cargo, expedited ground and air delivery of time-critical freight, heavy-haul/specialized, U.S.-Canada and U.S.-Mexico cross-border, intra-Mexico, project cargo and customs brokerage. Examples of the industries serviced by the transportation logistics segment include automotive products, building products, metals, chemicals, foodstuffs, heavy machinery, retail, electronics and military equipment. In addition, the transportation logistics segment provides transportation services to other transportation companies, including third party logistics and less-than-truckload service providers. Each of the independent commission sales agents has the opportunity to market all of the services provided by the transportation logistics segment. Billings for freight transportation services are typically charged to customers on a per shipment basis for the physical transportation of freight.

During 2017, the Company incorporated Landstar Metro, S.A.P.I. de C.V., a transportation logistics company (“Landstar Metro”), and Landstar Metro Servicios S.A.P.I. de C.V., a services company (“Landstar Servicios”), each based in Mexico City, Mexico. On September 20, 2017, Landstar Metro acquired substantially all of the assets of the asset-light transportation logistics business of a Mexican transportation logistics company. In connection with the acquisition, individuals affiliated with the seller subscribed in the aggregate for a 30% equity interest in each of Landstar Metro and Landstar Servicios. Landstar Metro provides freight and logistics services within the country of Mexico and in conjunction with Landstar’s U.S./Mexico cross-border services. Landstar Servicios provides various administrative, financial, operational, safety and compliance services to Landstar Metro. The results of operations from Landstar Metro and Landstar Servicios are presented as part of the Company’s transportation logistics segment.

The insurance segment is comprised of Signature Insurance Company (“Signature”), a wholly owned offshore insurance subsidiary, and Risk Management Claim Services, Inc. The insurance segment provides risk and claims management services to certain of Landstar’s operating subsidiaries. In addition, it reinsures certain risks of the Company’s BCO Independent Contractors and provides certain property and casualty insurance directly to certain of Landstar’s operating subsidiaries. Revenue at the insurance segment represents reinsurance premiums from third party insurance companies that provide insurance programs to BCO Independent Contractors where all or a portion of the risk is ultimately borne by Signature. Internal revenue for premiums billed by the insurance segment to the transportation logistics segment is calculated each fiscal period based primarily on an actuarial calculation of historical loss experience and is believed to approximate the cost that would have been incurred by the transportation logistics segment had similar insurance been obtained from an unrelated third party.

The accounting policies of the segments are the same as those described in the summary of significant accounting policies. The Company evaluates a segment’s performance based on operating income.

No single customer accounted for more than 10% of the Company’s consolidated revenue in fiscal years 2017, 2016 and 2015. Substantially all of the Company’s revenue is generated in North America, primarily through customers located in the United States.

The following tables summarize information about the Company’s reportable business segments as of and for the fiscal years ending December 30, 2017, December 31, 2016 and December 26, 2015 (in thousands):


	Transportation
	Logistics		Insurance		Total
2017
External revenue	$	3,599,382	$	46,982	$	3,646,364
Internal revenue				37,110		37,110
Investment income				2,498		2,498
Interest and debt expense		3,166				3,166
Depreciation and amortization		40,560				40,560
Operating income		209,615		34,353		243,968
Expenditures on long-lived assets		15,586				15,586
Goodwill		39,065				39,065
Capital lease additions		33,560				33,560
Total assets		1,132,766		219,694		1,352,460
2016
External revenue	$	3,121,210	$	46,424	$	3,167,634
Internal revenue				36,118		36,118
Investment income				1,502		1,502
Interest and debt expense		3,794				3,794
Depreciation and amortization		35,796				35,796
Operating income		187,813		35,438		223,251
Expenditures on long-lived assets		22,645				22,645
Goodwill		31,134				31,134
Capital lease additions		61,504				61,504
Total assets		913,667		182,924		1,096,591
2015
External revenue	$	3,276,677	$	44,414	$	3,321,091
Internal revenue				31,342		31,342
Investment income				1,396		1,396
Interest and debt expense		2,949				2,949
Depreciation and amortization		29,102				29,102
Operating income		207,883		33,823		241,706
Expenditures on long-lived assets		4,804				4,804
Goodwill		31,134				31,134
Capital lease additions		49,491				49,491
Total assets		842,550		148,968		991,518

Change in Accounting Estimate for Self-Insured Claims

12 Months Ended

Dec. 30, 2017

Change in Accounting Estimate for Self-Insured Claims

(14) Change in Accounting Estimate for Self-Insured Claims

Landstar provides for the estimated costs of self-insured claims primarily on an actuarial basis. The amount recorded for the estimated liability for claims incurred is based upon the facts and circumstances known on the applicable balance sheet date. The ultimate resolution of these claims may be for an amount greater or less than the amount estimated by management. The Company continually revises its existing claim estimates as new or revised information becomes available on the status of each claim. Historically, the Company has experienced both favorable and unfavorable development of prior years’ claims estimates.

The following table summarizes the effect of the increase in the cost of insurance claims resulting from unfavorable development of prior year self-insured claims estimates on operating income, net income attributable to Landstar System, Inc. and subsidiary and earnings per share attributable to Landstar System, Inc. and subsidiary in the consolidated statements of income for the fiscal years ended December 30, 2017, December 31, 2016 and December 26, 2015 (in thousands, except per share amounts):


	Fiscal Years Ended
	December 30, 2017		December 31, 2016		December 26, 2015
Operating income	$	4,144	$	1,079	$	4,852
Net income attributable to Landstar System, Inc. and subsidiary		2,578		667		2,999
Earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.06	$	0.02	$	0.07
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.06	$	0.02	$	0.07

Recent Accounting Pronouncements

12 Months Ended

Dec. 30, 2017

Recent Accounting Pronouncements

(15) Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2014-09—Revenue from Contracts with Customers (“ASU 2014-09”). ASU 2014-09 is a comprehensive revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. The standard requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. ASU 2014-09 became effective for the Company as of January 1, 2018 and permits either a full retrospective or a modified retrospective transition approach. The Company adopted this new standard effective as of January 1, 2018 under the modified retrospective transition method with a cumulative adjustment to retained earnings instead of retrospectively adjusting prior periods. The adoption of this standard will change the timing of revenue recognition for most of its transportation business from at delivery to over the transit period as the performance obligation is completed. Due to the Company’s average length of haul for truckload movements and direct costs of revenue, purchased transportation and commissions to agents, the Company does not expect this change to have a material impact on its results of operations, financial position or cash flows once implemented.

In February 2016, the FASB issued Accounting Standards Update 2016-02 – Leases (“ASU 2016-02”). ASU 2016-02 requires a company to recognize a right-of-use asset and lease liability for the obligation to make lease payments measured at the present value of the lease payments for all leases with terms greater than twelve months. Companies are required to use a modified retrospective transition approach to recognize leases at the beginning of the earliest period presented. ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018, and interim periods therein, and early adoption is permitted. ASU 2016-02 is not expected to have a material impact on the Company’s financial statements.

In March 2016, the FASB issued Accounting Standards Update 2016-09 – Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”), which is intended to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for annual periods beginning after December 15, 2016, and interim periods therein. As such, the Company adopted ASU 2016-09 during the first quarter of 2017 with an effective date of January 1, 2017. As a result of the adoption, the Company recognized excess tax benefits in the consolidated statement of income of $1,299,000 for fiscal year 2017. Prior period amounts have not been reclassified.

In June 2016, the FASB issued Accounting Standards Update 2016-13– Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires measurement and recognition of expected versus incurred credit losses for financial assets held. ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods therein. The Company is currently evaluating the impact of ASU 2016-13 on its financial statements.

Quarterly Financial Data

12 Months Ended

Dec. 30, 2017

Quarterly Financial Data

QUARTERLY FINANCIAL DATA

(Dollars in thousands, except per share amounts)

(Unaudited)


	Fourth Quarter 2017			Third Quarter 2017			Second Quarter 2017		First Quarter 2017
Revenue	$	1,051,592		$	943,430		$	870,434	$	780,908

Operating income	$	70,049		$	60,567		$	61,018	$	52,334

Income before income taxes	$	69,442		$	59,910		$	60,199	$	51,251
Income taxes		4,759			17,490			22,689		18,868

Net income	$	64,683		$	42,420		$	37,510	$	32,383

Less: Net loss attributable to noncontrolling interest		(69	)		(23	)		—		—

Net income attributable to Landstar System, Inc. and subsidiary	$	64,752		$	42,443		$	37,510	$	32,383

Earnings per common share attributable to Landstar System, Inc. and subsidiary(1)	$	1.54		$	1.01		$	0.89	$	0.77

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary(1)	$	1.54		$	1.01		$	0.89	$	0.77

Dividends per common share	$	1.60		$	0.10		$	0.09	$	0.09


	Fourth Quarter 2016			Third Quarter 2016			Second Quarter 2016		First Quarter 2016
Revenue	$	892,829		$	787,938		$	775,223	$	711,644

Operating income	$	63,765		$	58,461		$	53,093	$	47,932

Income before income taxes	$	62,696		$	57,513		$	52,205	$	47,043
Income taxes		23,122			21,235			19,891		17,859

Net income	$	39,574		$	36,278		$	32,314	$	29,184

Earnings per common share attributable to Landstar System, Inc. and subsidiary(1)	$	0.95		$	0.86		$	0.77	$	0.69

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary(1)	$	0.94		$	0.86		$	0.76	$	0.69

Dividends per common share	$	0.09		$	0.09		$	0.08	$	0.08

(1)	Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 30, 2017

Consolidation

Consolidation

Estimates

Estimates

The preparation of the consolidated financial statements requires the use of management’s estimates. Actual results could differ from those estimates.

Fiscal Year

Fiscal Year

Landstar’s fiscal year is the 52 or 53 week period ending the last Saturday in December.

Revenue Recognition

Revenue Recognition

Insurance Claim Costs

Insurance Claim Costs

Tires

Tires

Tires purchased as part of trailing equipment are capitalized as part of the cost of the equipment. Replacement tires are charged to expense when placed in service.

Cash and Cash Equivalents

Cash and Cash Equivalents

Included in cash and cash equivalents are all investments, except those provided for collateral, with an original maturity of 3 months or less.

Financial Instruments

Financial Instruments

Trade and Other Receivables

Trade and Other Receivables


	Balance at Beginning of Period		Charged to Costs and Expenses		Write-offs, Net of Recoveries			Balance at End of Period
For the Fiscal Year Ended December 30, 2017
Trade receivables	$	5,161	$	3,982	$	(3,012	)	$	6,131
Other receivables		6,549		3,450		(3,047	)		6,952
Other non-current receivables		244		7		—			251

	$	11,954	$	7,439	$	(6,059	)	$	13,334

For the Fiscal Year Ended December 31, 2016
Trade receivables	$	4,327	$	2,772	$	(1,938	)	$	5,161
Other receivables		5,555		2,963		(1,969	)		6,549
Other non-current receivables		238		—		6			244

	$	10,120	$	5,735	$	(3,901	)	$	11,954

For the Fiscal Year Ended December 26, 2015
Trade receivables	$	4,338	$	3,985	$	(3,996	)	$	4,327
Other receivables		5,103		1,897		(1,445	)		5,555
Other non-current receivables		230		8		—			238

	$	9,671	$	5,890	$	(5,441	)	$	10,120

Operating Property

Operating Property

Goodwill

Goodwill

Income Taxes

Income Taxes

Share-Based Payments

Share-Based Payments

Earnings Per Share

Earnings Per Share


	Fiscal Years
	2017		2016		2015
Average number of common shares outstanding		41,938		42,112		43,664
Incremental shares from assumed exercises of stock options		86		124		149

Average number of common shares and common share equivalents outstanding		42,024		42,236		43,813

Dividends Payable

Dividends Payable

Foreign Currency Translation

Foreign Currency Translation

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 30, 2017

Summary of Activity in Allowance for Doubtful Accounts

Following is a summary of the activity in the allowance for doubtful accounts for fiscal years ending December 30, 2017, December 31, 2016 and December 26, 2015 (in thousands):


	Balance at Beginning of Period		Charged to Costs and Expenses		Write-offs, Net of Recoveries			Balance at End of Period
For the Fiscal Year Ended December 30, 2017
Trade receivables	$	5,161	$	3,982	$	(3,012	)	$	6,131
Other receivables		6,549		3,450		(3,047	)		6,952
Other non-current receivables		244		7		—			251

	$	11,954	$	7,439	$	(6,059	)	$	13,334

For the Fiscal Year Ended December 31, 2016
Trade receivables	$	4,327	$	2,772	$	(1,938	)	$	5,161
Other receivables		5,555		2,963		(1,969	)		6,549
Other non-current receivables		238		—		6			244

	$	10,120	$	5,735	$	(3,901	)	$	11,954

For the Fiscal Year Ended December 26, 2015
Trade receivables	$	4,338	$	3,985	$	(3,996	)	$	4,327
Other receivables		5,103		1,897		(1,445	)		5,555
Other non-current receivables		230		8		—			238

	$	9,671	$	5,890	$	(5,441	)	$	10,120

Reconciliation of Average Number of Common Shares and Common Share Equivalents Outstanding


	Fiscal Years
	2017		2016		2015
Average number of common shares outstanding		41,938		42,112		43,664
Incremental shares from assumed exercises of stock options		86		124		149

Average number of common shares and common share equivalents outstanding		42,024		42,236		43,813

Other Comprehensive Income (Tables)

12 Months Ended

Dec. 30, 2017

Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes


	Unrealized Holding Gains (Losses) on Available-for-Sale Securities			Foreign Currency Translation			Total
Balance as of December 27, 2014	$	105		$	(1,290	)	$	(1,185	)
Other comprehensive loss		(199	)		(2,104	)		(2,303	)

Balance as of December 26, 2015		(94	)		(3,394	)		(3,488	)
Other comprehensive income		23			376			399

Balance as of December 31, 2016		(71	)		(3,018	)		(3,089	)
Other comprehensive loss		(73	)		—			(73	)

Balance as of December 30, 2017	$	(144	)	$	(3,018	)	$	(3,162	)

Investments (Tables)

12 Months Ended

Dec. 30, 2017

Amortized Cost and Fair Value of Available-for-Sale Investments

The amortized cost and fair values of available-for-sale investments are as follows at December 30, 2017 and December 31, 2016 (in thousands):


			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
December 30, 2017
Money market investments	$	27,895	$	—	$	—	$	27,895
Asset-backed securities		2,805		—		5		2,800
Corporate bonds and direct obligations of government agencies		80,442		117		335		80,224

Total	$	111,142	$	117	$	340	$	110,919

December 31, 2016
Money market investments	$	12,395	$	—	$	—	$	12,395
Asset-backed securities		4,027		3		19		4,011
Corporate bonds and direct obligations of government agencies		70,069		150		239		69,980
U.S. Treasury obligations		23,037		2		6		23,033

Total	$	109,528	$	155	$	264	$	109,419

Schedule of Unrealized Loss on Available-for-Sale Investments

For those available-for-sale investments with unrealized losses at December 30, 2017 and December 31, 2016, the following table summarizes the duration of the unrealized loss (in thousands):


	Less than 12 months				12 months or longer				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
December 30, 2017
Asset-backed securities	$	1,864	$	4	$	632	$	1	$	2,496	$	5
Corporate bonds and direct obligations of government agencies		41,322		220		14,016		115		55,338		335

Total	$	43,186	$	224	$	14,648	$	116	$	57,834	$	340

December 31, 2016
Asset-backed securities	$	1,363	$	6	$	2,314	$	13	$	3,677	$	19
Corporate bonds and direct obligations of government agencies		28,809		195		1,367		44		30,176		239
U.S. Treasury obligations		12,734		6		—		—		12,734		6

Total	$	42,906	$	207	$	3,681	$	57	$	46,587	$	264

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details

Income Taxes (Tables)

12 Months Ended

Dec. 30, 2017

Schedule of Provisions for Income Taxes

The provisions for income taxes consisted of the following (in thousands):


	Fiscal Years
	2017			2016		2015
Current:
Federal	$	72,025		$	68,548	$	74,289
State		8,312			6,668		9,550
Foreign		500			563		437

Total current	$	80,837		$	75,779	$	84,276

Deferred:
Federal	$	(17,110	)	$	6,104	$	6,524
State		79			224		268

Total deferred	$	(17,031	)	$	6,328	$	6,792

Income taxes	$	63,806		$	82,107	$	91,068

Schedule of Deferred Tax Assets and Liabilities

Temporary differences and carryforwards which gave rise to deferred tax assets and liabilities consisted of the following (in thousands):


	Dec. 30, 2017		Dec. 31, 2016
Deferred tax assets:
Receivable valuations	$	3,244	$	4,518
Share-based payments		2,182		1,185
Self-insured claims		4,688		6,270
Other		3,666		4,336

Total deferred tax assets	$	13,780	$	16,309

Deferred tax liabilities:
Operating property	$	43,105	$	59,720
Goodwill		3,773		5,883
Other		2,016		2,851

Total deferred tax liabilities	$	48,894	$	68,454

Net deferred tax liability	$	35,114	$	52,145

Schedule of Income Taxes Calculated on Income from Continuing Operations Before Income Taxes and Provision for Income Taxes

The following table summarizes the differences between income taxes calculated at the federal income tax rate of 35% on income before income taxes and the provisions for income taxes (in thousands):


	Fiscal Years
	2017			2016			2015
Income taxes at federal income tax rate	$	84,281		$	76,810		$	83,565
State income taxes, net of federal income tax benefit		5,417			4,505			7,201
Meals and entertainment exclusion		1,021			958			946
Share-based payments		(1,549	)		(239	)		(61	)
Section 199 deductions and R&D credits		(5,546	)		(250	)		—
Tax Reform Act		(19,530	)		—			—
Other, net		(288	)		323			(583	)

Income taxes	$	63,806		$	82,107		$	91,068

Schedule for Gross Unrecognized Tax Benefits

The following table summarizes the rollforward of the total amounts of gross unrecognized tax benefits for fiscal years 2017 and 2016 (in thousands):


	Fiscal Years
	2017			2016
Gross unrecognized tax benefits – beginning of the year	$	2,635		$	2,704
Gross increases related to current year tax positions		645			428
Gross increases related to prior year tax positions		2,189			596
Gross decreases related to prior year tax positions		(75	)		(399	)
Settlements		(100	)		(133	)
Lapse of statute of limitations		(482	)		(561	)

Gross unrecognized tax benefits – end of the year	$	4,812		$	2,635

Operating Property (Tables)

12 Months Ended

Dec. 30, 2017

Schedule of Operating Property

Operating property is summarized as follows (in thousands):


	Dec. 30, 2017		Dec. 31, 2016
Land	$	15,259	$	15,259
Buildings and improvements		57,758		56,413
Trailing equipment		363,377		342,813
Other equipment		58,317		48,732

Total operating property, gross		494,711		463,217
Less accumulated depreciation and amortization		218,700		190,374

Total operating property, net	$	276,011	$	272,843

Leases (Tables)

12 Months Ended

Dec. 30, 2017

Minimum Lease Payments

The future minimum lease payments under all noncancelable leases at December 30, 2017, principally for trailing equipment, are shown in the following table (in thousands):


	Capital Leases		Operating Leases
2018	$	44,810	$	302
2019		36,632		180
2020		29,261		5
2021		14,799		—
2022		5,588		—
Thereafter		—		—

Total future minimum lease payments		131,090	$	487

Less amount representing interest (2.0% to 3.5%)		5,977

Present value of minimum lease payments	$	125,113

Share-Based Payment Arrangements (Tables)

12 Months Ended

Dec. 30, 2017

Amounts Recognized in Financial Statements with Respect to Plans

Amounts recognized in the financial statements with respect to these Plans are as follows (in thousands):


	Fiscal Years
	2017			2016			2015
Total cost of the Plans during the period	$	7,721		$	2,747		$	6,925
Amount of related income tax benefit recognized during the period		(3,285	)		(1,238	)		(2,432	)

Net cost of the Plans during the period	$	4,436		$	1,509		$	4,493

Summary of Information Regarding Stock Options

The following table summarizes information regarding the Company’s outstanding stock options under the Plans:


	Options Outstanding					Options Exercisable
	Number of Options			Weighted Average Exercise Price per Share		Number of Options		Weighted Average Exercise Price per Share
Options at December 27, 2014		773,839		$	46.92		379,389	$	44.61
Exercised		(133,518	)	$	45.25
Forfeited		(3,100	)	$	52.91

Options at December 26, 2015		637,221		$	47.24		415,121	$	45.12
Exercised		(257,460	)	$	45.63
Forfeited		(7,200	)	$	53.63

Options at December 31, 2016		372,561		$	48.24		282,461	$	46.39
Exercised		(180,321	)	$	47.01
Forfeited		(3,200	)	$	52.47

Options at December 30, 2017		189,040		$	49.34		169,240	$	48.50

Summary of Stock Options Outstanding and Exercisable

The following tables summarize stock options outstanding and exercisable at December 30, 2017:


	Options Outstanding
Range of Exercise Prices Per Share	Number Outstanding		Weighted Average Remaining Contractual Term (years)		Weighted Average Exercise Price per Share
$35.64 - $40.00		15,400		1.6	$	36.46
$40.01 - $45.00		49,250		3.1	$	41.76
$45.01 - $58.06		124,390		4.5	$	53.93

		189,040		3.9	$	49.34


	Options Exercisable
Range of Exercise Prices Per Share	Number Exercisable		Weighted Average Remaining Contractual Term (years)		Weighted Average Exercise Price per Share
$35.64 - $40.00		15,400		1.6	$	36.46
$40.01 - $45.00		49,250		3.1	$	41.76
$45.01 - $56.40		104,590		4.4	$	53.45

		169,240		3.8	$	48.50

Restricted Stock Units (RSUs)

Schedule of Information on Restricted Stock Units

The following table summarizes information regarding the Company’s outstanding restricted stock unit (“RSU”) awards with either a performance condition or a market condition under the Plans:


	Number of			Weighted Average Grant Date
	RSUs			Fair Value
Outstanding at December 27, 2014		425,630		$	50.72
Granted		111,922		$	53.30
Vested		(91,382	)	$	51.98
Forfeited		(2,013	)	$	52.81

Outstanding at December 26, 2015		444,157		$	51.10
Granted		79,948		$	51.58
Vested		(81,344	)	$	53.08
Forfeited		(64,523	)	$	52.99

Outstanding at December 31, 2016		378,238		$	50.46
Granted		67,913		$	76.81
Forfeited		(58,779	)	$	46.00

Outstanding at December 30, 2017		387,372		$	55.75

Non Vested Restricted Stock and Deferred Stock Units

Schedule of Information on Non-Vested Restricted Stock and Deferred Stock Units

The following table summarizes information regarding the Company’s outstanding shares of non-vested restricted stock and Deferred Stock Units (defined below) under the Plans:


	Number of Shares and Deferred Stock Units			Weighted Average Grant Date Fair Value
Outstanding at December 27, 2014		23,353		$	54.90
Granted		1,197		$	62.46
Vested		(6,490	)	$	57.79

Outstanding at December 26, 2015		18,060		$	54.36
Granted		26,033		$	58.53
Vested		(15,684	)	$	53.03

Outstanding at December 31, 2016		28,409		$	58.91
Granted		42,573		$	84.47
Vested		(16,227	)	$	61.50

Outstanding at December 30, 2017		54,755		$	78.02

Segment Information (Tables)

12 Months Ended

Dec. 30, 2017

Information Regarding Reportable Business Segments


	Transportation
	Logistics		Insurance		Total
2017
External revenue	$	3,599,382	$	46,982	$	3,646,364
Internal revenue				37,110		37,110
Investment income				2,498		2,498
Interest and debt expense		3,166				3,166
Depreciation and amortization		40,560				40,560
Operating income		209,615		34,353		243,968
Expenditures on long-lived assets		15,586				15,586
Goodwill		39,065				39,065
Capital lease additions		33,560				33,560
Total assets		1,132,766		219,694		1,352,460
2016
External revenue	$	3,121,210	$	46,424	$	3,167,634
Internal revenue				36,118		36,118
Investment income				1,502		1,502
Interest and debt expense		3,794				3,794
Depreciation and amortization		35,796				35,796
Operating income		187,813		35,438		223,251
Expenditures on long-lived assets		22,645				22,645
Goodwill		31,134				31,134
Capital lease additions		61,504				61,504
Total assets		913,667		182,924		1,096,591
2015
External revenue	$	3,276,677	$	44,414	$	3,321,091
Internal revenue				31,342		31,342
Investment income				1,396		1,396
Interest and debt expense		2,949				2,949
Depreciation and amortization		29,102				29,102
Operating income		207,883		33,823		241,706
Expenditures on long-lived assets		4,804				4,804
Goodwill		31,134				31,134
Capital lease additions		49,491				49,491
Total assets		842,550		148,968		991,518

Change in Accounting Estimate for Self-Insured Claims (Tables)

12 Months Ended

Dec. 30, 2017

Effect of Increase in Cost of Insurance and Claims


	Fiscal Years Ended
	December 30, 2017		December 31, 2016		December 26, 2015
Operating income	$	4,144	$	1,079	$	4,852
Net income attributable to Landstar System, Inc. and subsidiary		2,578		667		2,999
Earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.06	$	0.02	$	0.07
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.06	$	0.02	$	0.07

Quarterly Financial Data (Tables)

12 Months Ended

Dec. 30, 2017

Quarterly Financial Data

QUARTERLY FINANCIAL DATA

(Dollars in thousands, except per share amounts)

(Unaudited)


	Fourth Quarter 2017			Third Quarter 2017			Second Quarter 2017		First Quarter 2017
Revenue	$	1,051,592		$	943,430		$	870,434	$	780,908

Operating income	$	70,049		$	60,567		$	61,018	$	52,334

Income before income taxes	$	69,442		$	59,910		$	60,199	$	51,251
Income taxes		4,759			17,490			22,689		18,868

Net income	$	64,683		$	42,420		$	37,510	$	32,383

Less: Net loss attributable to noncontrolling interest		(69	)		(23	)		—		—

Net income attributable to Landstar System, Inc. and subsidiary	$	64,752		$	42,443		$	37,510	$	32,383

Earnings per common share attributable to Landstar System, Inc. and subsidiary(1)	$	1.54		$	1.01		$	0.89	$	0.77

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary(1)	$	1.54		$	1.01		$	0.89	$	0.77

Dividends per common share	$	1.60		$	0.10		$	0.09	$	0.09


	Fourth Quarter 2016			Third Quarter 2016			Second Quarter 2016		First Quarter 2016
Revenue	$	892,829		$	787,938		$	775,223	$	711,644

Operating income	$	63,765		$	58,461		$	53,093	$	47,932

Income before income taxes	$	62,696		$	57,513		$	52,205	$	47,043
Income taxes		23,122			21,235			19,891		17,859

Net income	$	39,574		$	36,278		$	32,314	$	29,184

Earnings per common share attributable to Landstar System, Inc. and subsidiary(1)	$	0.95		$	0.86		$	0.77	$	0.69

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary(1)	$	0.94		$	0.86		$	0.76	$	0.69

Dividends per common share	$	0.09		$	0.09		$	0.08	$	0.08

(1)	Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.

Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 30, 2017 USD ($) $ / shares shares	Dec. 31, 2016 shares	Dec. 26, 2015 shares
Significant Accounting Policies [Line Items]
Number of reporting units	2
Stock options excluded from calculation of diluted earnings per share, antidilutive \| shares	0	0	0
Dividends payable per share \| $ / shares	$ 1.50
Dividend payable date	Jan. 26, 2018
Dividend record date	Jan. 12, 2018
Dividends payable	$ 62,985,000
Dividend declared date	Dec. 11, 2017
Buildings And Improvements
Significant Accounting Policies [Line Items]
Depreciated life	30 years
Trailing Equipment \| Maximum
Significant Accounting Policies [Line Items]
Depreciated life	10 years
Trailing Equipment \| Minimum
Significant Accounting Policies [Line Items]
Depreciated life	7 years
Hardware And Software \| Maximum
Significant Accounting Policies [Line Items]
Depreciated life	7 years
Hardware And Software \| Minimum
Significant Accounting Policies [Line Items]
Depreciated life	3 years
Commercial Trucking Claims \| Maximum
Significant Accounting Policies [Line Items]
Company retained liability per claim	$ 5,000,000
Commercial Trucking Claims \| Maximum \| Additional Retained Liability for Claims on or after May 1, 2016 through April 30, 2017
Significant Accounting Policies [Line Items]
Company retained aggregate liability	700,000
Commercial Trucking Claims \| Maximum \| Additional Retained Liability for Claims on or after May 1, 2017 through April 30, 2018
Significant Accounting Policies [Line Items]
Company retained aggregate liability	500,000
General Liability Claim \| Maximum
Significant Accounting Policies [Line Items]
Company retained liability per claim	1,000,000
Workers' Compensation Claim \| Maximum
Significant Accounting Policies [Line Items]
Company retained liability per claim	250,000
Cargo Claim \| Maximum
Significant Accounting Policies [Line Items]
Company retained liability per claim	$ 250,000

Summary of Activity in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 11,954	$ 10,120	$ 9,671
Charged to Costs and Expenses	7,439	5,735	5,890
Write-offs, Net of Recoveries	(6,059)	(3,901)	(5,441)
Balance at End of Period	13,334	11,954	10,120
Trade Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	5,161	4,327	4,338
Charged to Costs and Expenses	3,982	2,772	3,985
Write-offs, Net of Recoveries	(3,012)	(1,938)	(3,996)
Balance at End of Period	6,131	5,161	4,327
Other Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	6,549	5,555	5,103
Charged to Costs and Expenses	3,450	2,963	1,897
Write-offs, Net of Recoveries	(3,047)	(1,969)	(1,445)
Balance at End of Period	6,952	6,549	5,555
Other Non-Current Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	244	238	230
Charged to Costs and Expenses	7		8
Write-offs, Net of Recoveries		6
Balance at End of Period	$ 251	$ 244	$ 238

Reconciliation of Average Number of Common Shares and Common Share Equivalents Outstanding (Detail) - shares	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Average number of common shares outstanding	41,938,000	42,112,000	43,664,000
Incremental shares from assumed exercises of stock options	86,000	124,000	149,000
Average number of common shares and common share equivalents outstanding	42,024,000	42,236,000	43,813,000

Acquired Business and Noncontrolling Interests - Additional Information (Detail) - USD ($)		12 Months Ended
	Sep. 20, 2017	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Goodwill		$ 39,065,000	$ 31,134,000	$ 31,134,000
Fletes Avella \| Landstar Metro
Payments to acquire businesses, gross	$ 8,460,000
Business combination, recognized identifiable assets acquired and liabilities assumed, liabilities		1,900,000
Ownership interest acquired by affiliates	30.00%
Goodwill		$ 8,800,000
Percentage of goodwill estimated to be deductible for tax purposes		70.00%
Percentage of goodwill estimated to be deductible after purchase of noncontrolling interests by the company		100.00%
One-time costs related to completion of acquisition		$ 1,000,000
One-time costs related to completion of acquisition, per share		$ 0.01
One-time costs related to completion of acquisition, per share diluted		$ 0.01
Fletes Avella \| Landstar Servicios
Ownership interest acquired by affiliates	30.00%

Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 542,557
Other comprehensive income (loss)	(73)	$ 399	$ (2,303)
Ending Balance	650,672	542,557
Unrealized Holding Gains (Losses) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(71)	(94)	105
Other comprehensive income (loss)	(73)	23	(199)
Ending Balance	(144)	(71)	(94)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,018)	(3,394)	(1,290)
Other comprehensive income (loss)		376	(2,104)
Ending Balance	(3,018)	(3,018)	(3,394)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,089)	(3,488)	(1,185)
Ending Balance	$ (3,162)	$ (3,089)	$ (3,488)

Investments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Investments maximum maturity period	5 years
Unrealized losses, net of unrealized gains, on the investments in the bond portfolio	$ (223)	$ (109)
Guarantee Payment of Insurance Claims
Schedule of Available-for-sale Securities [Line Items]
Letters of credit outstanding	59,436
Current Investments
Schedule of Available-for-sale Securities [Line Items]
Investments providing collateral for letters of credit to guarantee insurance claims	48,928
Non-Current Investments
Schedule of Available-for-sale Securities [Line Items]
Investments providing collateral for letters of credit to guarantee insurance claims	17,112
Total non-current investments	$ 61,991

Amortized Cost and Fair Value of Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 111,142	$ 109,528
Gross Unrealized Gains	117	155
Gross Unrealized Losses	340	264
Fair Value	110,919	109,419
Money market investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,895	12,395
Fair Value	27,895	12,395
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,805	4,027
Gross Unrealized Gains		3
Gross Unrealized Losses	5	19
Fair Value	2,800	4,011
Corporate bonds and direct obligations of government agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	80,442	70,069
Gross Unrealized Gains	117	150
Gross Unrealized Losses	335	239
Fair Value	$ 80,224	69,980
U.S. Treasury obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		23,037
Gross Unrealized Gains		2
Gross Unrealized Losses		6
Fair Value		$ 23,033

Schedule of Unrealized Loss on Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value	$ 43,186	$ 42,906
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss	224	207
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value	14,648	3,681
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss	116	57
Available-for-sale investments with unrealized losses, Fair Value, Total	57,834	46,587
Available-for-sale investments with unrealized losses, Unrealized Loss, Total	340	264
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value	1,864	1,363
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss	4	6
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value	632	2,314
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss	1	13
Available-for-sale investments with unrealized losses, Fair Value, Total	2,496	3,677
Available-for-sale investments with unrealized losses, Unrealized Loss, Total	5	19
Corporate bonds and direct obligations of government agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value	41,322	28,809
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss	220	195
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value	14,016	1,367
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss	115	44
Available-for-sale investments with unrealized losses, Fair Value, Total	55,338	30,176
Available-for-sale investments with unrealized losses, Unrealized Loss, Total	$ 335	239
U.S. Treasury obligations
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value		12,734
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss		6
Available-for-sale investments with unrealized losses, Fair Value, Total		12,734
Available-for-sale investments with unrealized losses, Unrealized Loss, Total		$ 6

Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Tax Disclosure [Line Items]
Federal, Current									$ 72,025	$ 68,548	$ 74,289
State, Current									8,312	6,668	9,550
Foreign, Current									500	563	437
Total current									80,837	75,779	84,276
Federal, Deferred									(17,110)	6,104	6,524
State, Deferred									79	224	268
Total deferred									(17,031)	6,328	6,792
Income taxes	$ 4,759	$ 17,490	$ 22,689	$ 18,868	$ 23,122	$ 21,235	$ 19,891	$ 17,859	$ 63,806	$ 82,107	$ 91,068

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Taxes [Line Items]
Federal income tax rate		35.00%
Tax cuts and jobs act of 2017 incomplete accounting revaluation deferred tax liabilities provisional income tax expense (benefit)		$ 20,430
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation foreign earnings and profits provisional income tax expense (benefit)		17,981
Tax cuts and jobs act of 2017, incomplete accounting, provisional income tax expense (benefit)		900
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable		$ 500
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable period		8 years
Net unrecognized tax benefits		$ 3,670	$ 1,829
Accrued for estimated interest and penalties		627	547
Income taxes paid		$ 86,607	$ 69,067	$ 74,619
Scenario, Forecast
Income Taxes [Line Items]
Federal income tax rate	21.00%
Landstar Metro
Income Taxes [Line Items]
Ownership in subsidiaries, percentage		70.00%
Landstar Servicios
Income Taxes [Line Items]
Ownership in subsidiaries, percentage		70.00%
Accounting Standards Update 2016-09
Income Taxes [Line Items]
Excess tax benefit from stock-based awards		$ 1,299

Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Receivable valuations	$ 3,244	$ 4,518
Share-based payments	2,182	1,185
Self-insured claims	4,688	6,270
Other	3,666	4,336
Total deferred tax assets	13,780	16,309
Operating property	43,105	59,720
Goodwill	3,773	5,883
Other	2,016	2,851
Total deferred tax liabilities	48,894	68,454
Net deferred tax liability	$ 35,114	$ 52,145

Schedule of Income Taxes Calculated on Income from Continuing Operations Before Income Taxes and Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Tax Disclosure [Line Items]
Income taxes at federal income tax rate									$ 84,281	$ 76,810	$ 83,565
State income taxes, net of federal income tax benefit									5,417	4,505	7,201
Meals and entertainment exclusion									1,021	958	946
Share-based payments									(1,549)	(239)	(61)
Section 199 deductions and R&D credits									(5,546)	(250)
Tax Reform Act									(19,530)
Other, net									(288)	323	(583)
Income taxes	$ 4,759	$ 17,490	$ 22,689	$ 18,868	$ 23,122	$ 21,235	$ 19,891	$ 17,859	$ 63,806	$ 82,107	$ 91,068

Schedule for Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Gross unrecognized tax benefits - beginning of the year	$ 2,635	$ 2,704
Gross increases related to current year tax positions	645	428
Gross increases related to prior year tax positions	2,189	596
Gross decreases related to prior year tax positions	(75)	(399)
Settlements	(100)	(133)
Lapse of statute of limitations	(482)	(561)
Gross unrecognized tax benefits - end of the year	$ 4,812	$ 2,635

Operating Property (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Land	$ 15,259	$ 15,259
Buildings and improvements	57,758	56,413
Trailing equipment	363,377	342,813
Other equipment	58,317	48,732
Total operating property, gross	494,711	463,217
Less accumulated depreciation and amortization	218,700	190,374
Total operating property, net	$ 276,011	$ 272,843

Operating Property - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Property, Plant and Equipment [Line Items]
Operating property under capital leases	$ 239,438	$ 249,717
Operating property under capital leases, net of accumulated depreciation and amortization	171,658	183,763
Capital leases	$ 33,560	$ 61,504	$ 49,491

Retirement Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Retirement Plans [Line Items]
Defined contribution plan maximum employee contribution as a percentage of base salary	75.00%
Expense for the Company-sponsored defined contribution plan	$ 2,056	$ 2,074	$ 1,901
First 3% of Contributions on Defined Contribution Plan
Retirement Plans [Line Items]
Defined contribution plan employer contribution as a percentage of base salary	100.00%
Threshold to determine company matching percentage	3.00%
Next 2% of Contributions on Defined Contribution Plan
Retirement Plans [Line Items]
Defined contribution plan employer contribution as a percentage of base salary	50.00%
Threshold to determine company matching percentage	2.00%

Debt - Additional Information (Detail) - USD ($)	12 Months Ended
Debt - Additional Information (Detail) - USD ($)	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Debt Instrument [Line Items]
Debt Outstanding Excluding Capital Lease Obligations	$ 0	$ 0
Interest paid	$ 3,891,000	3,794,000	$ 3,012,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, initiation date	Jun. 02, 2016
Credit facility, expiration date	Jun. 02, 2021
Credit facility, borrowing capacity	$ 250,000,000
Credit facility, maximum borrowing capacity	$ 400,000,000
Security interest on voting capital stock	65.00%
Security interest on non voting capital stock	100.00%
Borrowings outstanding	$ 0	$ 0
Credit facility, debt covenants compliance	The Company is currently in compliance with all of the debt covenants under the Credit Agreement.
Revolving Credit Facility \| Federal Reserve Bank of New York
Debt Instrument [Line Items]
Borrowings, basis spread on variable rate	0.50%
Revolving Credit Facility \| London Interbank Offered Rate
Debt Instrument [Line Items]
Borrowings, basis spread on variable rate	1.25%
Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Credit facility, unused credit commitment fee	0.15%
Credit facility event of default, minimum percentage that a person or group should acquire outstanding capital stock	35.00%
Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Credit facility, unused credit commitment fee	0.25%
Maximum Leverage ratio beyond which amount of cash dividends and other distributions to stockholders is limited	250.00%
Letter of Credit
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 50,000,000

Minimum Lease Payments (Detail) $ in Thousands	Dec. 30, 2017 USD ($)
Capital Leases And Operating Leases [Line Items]
Capital Leases, 2018	$ 44,810
Capital Leases, 2019	36,632
Capital Leases, 2020	29,261
Capital Leases, 2021	14,799
Capital Leases, 2022	5,588
Thereafter	0
Capital leases, future minimum payments due, Total	131,090
Less amount representing interest (2.0% to 3.5%)	5,977
Present value of minimum lease payments	125,113
Operating Leases, 2018	302
Operating Leases, 2019	180
Operating Leases, 2020	5
Operating Leases, 2021	0
Operating Leases, 2022	0
Thereafter	0
Operating lease, future minimum payments due, Total	$ 487

Share-Based Payment Arrangements - Additional Information (Detail) $ in Thousands		12 Months Ended
	May 01, 2015 shares	Dec. 30, 2017 USD ($) EquityPlan shares	Dec. 31, 2016 USD ($) shares	Dec. 26, 2015 USD ($) shares	Dec. 27, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employee equity incentive plans \| EquityPlan		2
Income tax benefit realized on disqualifying dispositions of stock acquired by exercise of incentive stock options \| $		$ 339	$ 451
Accounting Standards Update 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit from stock-based awards \| $		$ 1,299
2013 Directors Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for issuance \| shares		115,000
Common stock reserved for issuance \| shares		78,682
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount rate on stock awards		7.00%
Stock awards granted \| shares		67,913	79,948	111,922
Recognized share-based compensation expense \| $		$ 5,849	$ 849	$ 4,943
Unrecognized compensation cost expected to be recognized over period, years		2 years 7 months 6 days
Unvested units \| shares		387,372	378,238	444,157	425,630
Restricted Stock Units (RSUs) \| May 2015 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target available for common share issuance	100.00%
Stock awards granted \| shares	20,000
Restricted Stock Units (RSUs) \| February 2017 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target available for common share issuance		100.00%
Restricted Stock Units (RSUs) \| January 2016 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target available for common share issuance		100.00%
Restricted Stock Units (RSUs) \| January 2015 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target available for common share issuance		100.00%
Restricted Stock Units (RSUs) \| Performance Unit Awards Twenty Thirteen
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost \| $		$ 3,400
Unvested units \| shares		68,592
Non Vested Restricted Stock and Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted \| shares		42,573	26,033	1,197
Unrecognized compensation cost \| $		$ 2,967
Unrecognized compensation cost expected to be recognized over period, years		2 years 10 months 25 days
Unvested units \| shares		54,755	28,409	18,060	23,353
Terms of award		The Company’s common stock on the date of grant. Shares of non-vested restricted stock are generally subject to vesting in three equal annual installments either on the first, second and third anniversary of the date of the grant or the third, fourth and fifth anniversary of the date of the grant, or 100% on the first anniversary of the date of the grant. For restricted stock awards granted under the 2013 DSCP plan, each recipient may elect to defer receipt of shares and instead receive restricted stock units (“Deferred Stock Units”), which represent contingent rights to receive shares of the Company’s common stock on the date of recipient separation from service from the Board of Directors, or, if earlier, upon a change in control event of the Company. Deferred Stock Units become vested 100% on the first anniversary of the date of the grant.
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Terms of award		Options outstanding under the Plans generally become exercisable in either five equal annual installments commencing on the first anniversary of the date of grant or 100% on the fifth anniversary from the date of grant, subject to acceleration in certain circumstances. All options granted under the Plans expire on the tenth anniversary of the date of grant. Under the Plans, the exercise price of each option equals the fair market value of the Company's Common Stock on the date of grant.
Stock option, grant \| shares		0	0	0
Stock options outstanding, intrinsic value \| $		$ 10,352
Intrinsic value of stock options exercisable \| $		9,410
Total intrinsic value of stock options exercised during periods \| $		7,599	$ 7,427	$ 2,954
Unrecognized compensation cost, stock options \| $		29
Directors Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
FMV of restricted shares granted to Directors upon election \| $		$ 110	$ 110	$ 225
Restricted shares granted \| shares		6,575	7,762	1,197
Compensation cost on restricted and Deferred Stock Units granted \| $		$ 651	$ 591	$ 419
Directors Stock Compensation Plan \| Class III Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
FMV of restricted shares granted to Directors upon election \| $		$ 0	$ 35
Deferred Stock Units D S Us [Member] \| Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted \| shares		1,315
Maximum \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost \| $		$ 28,400
Maximum \| Restricted Stock Units (RSUs) \| May 2015 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of target available for common share issuance	150.00%
Maximum \| Restricted Stock Units (RSUs) \| February 2017 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of target available for common share issuance		200.00%
Maximum \| Restricted Stock Units (RSUs) \| January 2016 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of target available for common share issuance		200.00%
Maximum \| Restricted Stock Units (RSUs) \| January 2015 Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of target available for common share issuance		200.00%
Maximum \| Restricted Stock Units (RSUs) \| Prior to 2015 grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of target available for common share issuance		100.00%
2011 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for issuance \| shares		6,000,000
2013 Directors Stock Compensation Plan \| Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock vesting percentage		100.00%
Other Stock Compensation Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance \| shares		4,678,411

Amounts Recognized in Financial Statements with Respect to Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total cost of the Plans during the period	$ 7,721	$ 2,747	$ 6,925
Amount of related income tax benefit recognized during the period	(3,285)	(1,238)	(2,432)
Net cost of the Plans during the period	$ 4,436	$ 1,509	$ 4,493

Schedule of Information on Restricted Stock Units (Detail) - Restricted Stock Units (RSUs) - $ / shares	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Number of Shares
Beginning Balance	378,238	444,157	425,630
Granted	67,913	79,948	111,922
Vested		(81,344)	(91,382)
Forfeited	(58,779)	(64,523)	(2,013)
Ending Balance	387,372	378,238	444,157
Weighted Average Grant Date Fair Value
Beginning Balance	$ 50.46	$ 51.10	$ 50.72
Granted	76.81	51.58	53.30
Vested		53.08	51.98
Forfeited	46.00	52.99	52.81
Ending Balance	$ 55.75	$ 50.46	$ 51.10

Summary of Information Regarding Stock Options (Detail) - $ / shares	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Number of Options
Beginning Balance, number of options	372,561	637,221	773,839
Exercised, number of options	(180,321)	(257,460)	(133,518)
Forfeited, number of options	(3,200)	(7,200)	(3,100)
Ending Balance, number of options	189,040	372,561	637,221
Weighted Average Exercise Price per Share
Beginning Balance, Weighted Average Exercise Price per Share	$ 48.24	$ 47.24	$ 46.92
Exercised, Weighted Average Exercise Price per Share	47.01	45.63	45.25
Forfeited, Weighted Average Exercise Price per Share	52.47	53.63	52.91
Ending Balance, Weighted Average Exercise Price per Share	$ 49.34	$ 48.24	$ 47.24
Options Exercisable, Number of Options
Options exercisable at the beginning, Number of Options	282,461	415,121	379,389
Options exercisable at the ending, Number of Options	169,240	282,461	415,121
Options Exercisable, Weighted Average Exercise Price per Share
Options exercisable at the beginning, Weighted Average Exercise Price per Share	$ 46.39	$ 45.12	$ 44.61
Options exercisable at the ending, Weighted Average Exercise Price per Share	$ 48.50	$ 46.39	$ 45.12

Summary Stock Options Outstanding and Exercisable (Detail)	12 Months Ended
	Dec. 30, 2017 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding \| shares	189,040
Options Exercisable \| shares	169,240
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 10 months 25 days
Options Exercisable, Weighted Average Contractual Life (Years)	3 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price per Share	$ 49.34
Options Exercisable, Weighted Average Exercise Price	48.50
Range One
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	35.64
Maximum Exercise Price	$ 40.00
Options Outstanding \| shares	15,400
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	1 year 7 months 6 days
Options Outstanding, Weighted Average Exercise Price per Share	$ 36.46
Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	40.01
Maximum Exercise Price	$ 45.00
Options Outstanding \| shares	49,250
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price per Share	$ 41.76
Range Three
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	45.01
Maximum Exercise Price	$ 58.06
Options Outstanding \| shares	124,390
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	4 years 6 months
Options Outstanding, Weighted Average Exercise Price per Share	$ 53.93
Range Four
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	35.64
Maximum Exercise Price	$ 40.00
Options Exercisable \| shares	15,400
Options Exercisable, Weighted Average Contractual Life (Years)	1 year 7 months 6 days
Options Exercisable, Weighted Average Exercise Price	$ 36.46
Range Five
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	40.01
Maximum Exercise Price	$ 45.00
Options Exercisable \| shares	49,250
Options Exercisable, Weighted Average Contractual Life (Years)	3 years 1 month 6 days
Options Exercisable, Weighted Average Exercise Price	$ 41.76
Range Six
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Exercise Price	45.01
Maximum Exercise Price	$ 56.40
Options Exercisable \| shares	104,590
Options Exercisable, Weighted Average Contractual Life (Years)	4 years 4 months 24 days
Options Exercisable, Weighted Average Exercise Price	$ 53.45

Schedule of Information on Non - Vested Restricted Stock Units (Detail) - Non Vested Restricted Stock and Deferred Stock Units - $ / shares	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Number of Shares and Deferred Stock Units
Beginning Balance	28,409	18,060	23,353
Granted	42,573	26,033	1,197
Vested	(16,227)	(15,684)	(6,490)
Ending Balance	54,755	28,409	18,060
Weighted Average Grant Date Fair Value
Beginning Balance	$ 58.91	$ 54.36	$ 54.90
Granted	84.47	58.53	62.46
Vested	61.50	53.03	57.79
Ending Balance	$ 78.02	$ 58.91	$ 54.36

Equity - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015	Dec. 11, 2017	May 19, 2015
Equity [Line Items]
Shares authorized for repurchase				1,963,875	3,000,000
Remaining shares available for repurchase	3,000,000
Total cost of repurchase of common stock	$ 0	$ 50,516	$ 161,152
Preferred stock, shares authorized and unissued	2,000,000
Treasury Stock
Equity [Line Items]
Common stock repurchased during period, shares	0	773,281	2,497,748

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Sep. 20, 2017
Fletes Avella \| Landstar Metro
Commitments and Contingencies Disclosure [Line Items]
Ownership interest acquired by affiliates		30.00%
Fletes Avella \| Landstar Servicios
Commitments and Contingencies Disclosure [Line Items]
Ownership interest acquired by affiliates		30.00%
Revolving Credit Facility
Commitments and Contingencies Disclosure [Line Items]
Letters of credit outstanding	$ 33,124
Guarantee Payment of Insurance Claims
Commitments and Contingencies Disclosure [Line Items]
Letters of credit outstanding	$ 59,436

Segment Information - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jul. 01, 2017 USD ($)	Apr. 01, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 24, 2016 USD ($)	Jun. 25, 2016 USD ($)	Mar. 26, 2016 USD ($)	Dec. 30, 2017 USD ($) Customer Segment	Dec. 31, 2016 USD ($) Customer	Dec. 26, 2015 USD ($) Customer	Sep. 20, 2017
Segment Reporting Information [Line Items]
External revenue \| $	$ 1,051,592	$ 943,430	$ 870,434	$ 780,908	$ 892,829	$ 787,938	$ 775,223	$ 711,644	$ 3,646,364	$ 3,167,634	$ 3,321,091
Number of segments \| Segment									2
Number of customers accounting for 10 percent or more of total revenue \| Customer									0	0	0
No single customer accounted for benchmark percentage to be considered major customer									10.00%	10.00%	10.00%
Fletes Avella \| Landstar Metro
Segment Reporting Information [Line Items]
Ownership interest acquired by affiliates												30.00%
Fletes Avella \| Landstar Servicios
Segment Reporting Information [Line Items]
Ownership interest acquired by affiliates												30.00%

Information Regarding Reportable Business Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Segment Reporting Information [Line Items]
External revenue	$ 1,051,592	$ 943,430	$ 870,434	$ 780,908	$ 892,829	$ 787,938	$ 775,223	$ 711,644	$ 3,646,364	$ 3,167,634	$ 3,321,091
Internal revenue									37,110	36,118	31,342
Investment income									2,498	1,502	1,396
Interest and debt expense									3,166	3,794	2,949
Depreciation and amortization									40,560	35,796	29,102
Operating income	70,049	$ 60,567	$ 61,018	$ 52,334	63,765	$ 58,461	$ 53,093	$ 47,932	243,968	223,251	241,706
Expenditures on long-lived assets									15,586	22,645	4,804
Goodwill	39,065				31,134				39,065	31,134	31,134
Capital lease additions									33,560	61,504	49,491
Total assets	1,352,460				1,096,591				1,352,460	1,096,591	991,518
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue									3,599,382	3,121,210	3,276,677
Interest and debt expense									3,166	3,794	2,949
Depreciation and amortization									40,560	35,796	29,102
Operating income									209,615	187,813	207,883
Expenditures on long-lived assets									15,586	22,645	4,804
Goodwill	39,065				31,134				39,065	31,134	31,134
Capital lease additions									33,560	61,504	49,491
Total assets	1,132,766				913,667				1,132,766	913,667	842,550
Insurance
Segment Reporting Information [Line Items]
External revenue									46,982	46,424	44,414
Internal revenue									37,110	36,118	31,342
Investment income									2,498	1,502	1,396
Operating income									34,353	35,438	33,823
Total assets	$ 219,694				$ 182,924				$ 219,694	$ 182,924	$ 148,968

Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

12 Months Ended

Dec. 30, 2017

Sep. 30, 2017

Jul. 01, 2017

Apr. 01, 2017

Dec. 31, 2016

Sep. 24, 2016

Jun. 25, 2016

Mar. 26, 2016

Dec. 30, 2017

Dec. 31, 2016

Dec. 26, 2015

Change in Accounting Estimate [Line Items]

Operating income

$ 70,049

$ 60,567

$ 61,018

$ 52,334

$ 63,765

$ 58,461

$ 53,093

$ 47,932

$ 243,968

$ 223,251

$ 241,706

Net income attributable to Landstar System, Inc. and subsidiary

$ 64,752

$ 42,443

$ 37,510

$ 32,383

$ 177,088

$ 137,350

$ 147,689

Earnings per share attributable to Landstar System, Inc. and subsidiary

$ 1.54

^[1]

$ 1.01

^[1]

$ 0.89

^[1]

$ 0.77

^[1]

$ 0.95

^[1]

$ 0.86

^[1]

$ 0.77

^[1]

$ 0.69

^[1]

$ 4.22

$ 3.26

$ 3.38

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary

$ 1.54

^[1]

$ 1.01

^[1]

$ 0.89

^[1]

$ 0.77

^[1]

$ 0.94

^[1]

$ 0.86

^[1]

$ 0.76

^[1]

$ 0.69

^[1]

$ 4.21

$ 3.25

$ 3.37

Development of Prior Year Self Insured Claims Estimates

Change in Accounting Estimate [Line Items]

Operating income

$ 4,144

$ 1,079

$ 4,852

Net income attributable to Landstar System, Inc. and subsidiary

$ 2,578

$ 667

$ 2,999

Earnings per share attributable to Landstar System, Inc. and subsidiary

$ 0.06

$ 0.02

$ 0.07

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary

$ 0.06

$ 0.02

$ 0.07

[1]	Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.

Quarterly Financial Data (Detail) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

12 Months Ended

Dec. 30, 2017

Sep. 30, 2017

Jul. 01, 2017

Apr. 01, 2017

Dec. 31, 2016

Sep. 24, 2016

Jun. 25, 2016

Mar. 26, 2016

Dec. 30, 2017

Dec. 31, 2016

Dec. 26, 2015

Schedule Of Quarterly Financial Data [Line Items]

Revenue

$ 1,051,592

$ 943,430

$ 870,434

$ 780,908

$ 892,829

$ 787,938

$ 775,223

$ 711,644

$ 3,646,364

$ 3,167,634

$ 3,321,091

Operating income

70,049

60,567

61,018

52,334

63,765

58,461

53,093

47,932

243,968

223,251

241,706

Income before income taxes

69,442

59,910

60,199

51,251

62,696

57,513

52,205

47,043

240,802

219,457

238,757

Income taxes

4,759

17,490

22,689

18,868

23,122

21,235

19,891

17,859

63,806

82,107

91,068

Net income

64,683

42,420

37,510

32,383

$ 39,574

$ 36,278

$ 32,314

$ 29,184

176,996

137,350

147,689

Less: Net loss attributable to noncontrolling interest

(69)

(23)

Net income attributable to Landstar System, Inc. and subsidiary

$ 64,752

$ 42,443

$ 37,510

$ 32,383

$ 177,088

$ 137,350

$ 147,689

Earnings per common share attributable to Landstar System, Inc. and subsidiary

$ 1.54

^[1]

$ 1.01

^[1]

$ 0.89

^[1]

$ 0.77

^[1]

$ 0.95

^[1]

$ 0.86

^[1]

$ 0.77

^[1]

$ 0.69

^[1]

$ 4.22

$ 3.26

$ 3.38

Diluted earnings per share attributable to Landstar System, Inc. and subsidiary

1.54

^[1]

1.01

^[1]

0.89

^[1]

0.77

^[1]

0.94

^[1]

0.86

^[1]

0.76

^[1]

0.69

^[1]

4.21

3.25

3.37

Dividends per common share

$ 1.60

$ 0.10

$ 0.09

$ 0.08

$ 1.88

$ 0.34

$ 0.30

[1]	Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.

Minimum Lease Payments (Parenthetical) (Detail)	12 Months Ended
Minimum Lease Payments (Parenthetical) (Detail)	Dec. 30, 2017
Minimum
Capital Leases And Operating Leases [Line Items]
Capital leases, future minimum payments, interest included in payments, interest rate	2.00%
Maximum
Capital Leases And Operating Leases [Line Items]
Capital leases, future minimum payments, interest included in payments, interest rate	3.50%