1001 - Document - Cover Page link:presentationLink link:definitionLink link:calculationLink 1002 - Statement - Consolidated Balance Sheets link:presentationLink link:definitionLink link:calculationLink 1003 - Statement - Consolidated Balance Sheets (Parenthetical) link:presentationLink link:definitionLink link:calculationLink 1004 - Statement - Consolidated Statements of Income link:presentationLink link:definitionLink link:calculationLink 1005 - Statement - Consolidated Statements of Comprehensive Income link:presentationLink link:definitionLink link:calculationLink 1006 - Statement - Consolidated Statements of Comprehensive Income (Parenthetical) link:presentationLink link:definitionLink link:calculationLink 1007 - Statement - Consolidated Statements of Cash Flows link:presentationLink link:definitionLink link:calculationLink 1008 - Statement - Consolidated Statements of Changes in Equity link:presentationLink link:definitionLink link:calculationLink 1009 - Statement - Consolidated Statements of Changes in Equity (Parenthetical) link:presentationLink link:definitionLink link:calculationLink 999001 - Disclosure - Significant Accounting Policies link:presentationLink link:definitionLink link:calculationLink 999002 - Disclosure - Other Comprehensive Income link:presentationLink link:definitionLink link:calculationLink 999003 - Disclosure - Investments link:presentationLink link:definitionLink link:calculationLink 999004 - Disclosure - Income Taxes link:presentationLink link:definitionLink link:calculationLink 999005 - Disclosure - Operating Property link:presentationLink link:definitionLink link:calculationLink 999006 - Disclosure - Retirement Plan link:presentationLink link:definitionLink link:calculationLink 999007 - Disclosure - Debt link:presentationLink link:definitionLink link:calculationLink 999008 - Disclosure - Leases link:presentationLink link:definitionLink link:calculationLink 999009 - Disclosure - Share-Based Payment Arrangements link:presentationLink link:definitionLink link:calculationLink 999010 - Disclosure - Equity link:presentationLink link:definitionLink link:calculationLink 999011 - Disclosure - Commitments and Contingencies link:presentationLink link:definitionLink link:calculationLink 999012 - Disclosure - Segment Information link:presentationLink link:definitionLink link:calculationLink 999013 - Disclosure - Change in Accounting Estimate for Self-Insured Claims link:presentationLink link:definitionLink link:calculationLink 999014 - Disclosure - Equity Investment link:presentationLink link:definitionLink link:calculationLink 999015 - Disclosure - Recent Accounting Pronouncements link:presentationLink link:definitionLink link:calculationLink 999016 - Disclosure - Significant Accounting Policies (Policies) link:presentationLink link:definitionLink link:calculationLink 999017 - Disclosure - Significant Accounting Policies (Tables) link:presentationLink link:definitionLink link:calculationLink 999018 - Disclosure - Other Comprehensive Income (Tables) link:presentationLink link:definitionLink link:calculationLink 999019 - Disclosure - Investments (Tables) link:presentationLink link:definitionLink link:calculationLink 999020 - Disclosure - Income Taxes (Tables) link:presentationLink link:definitionLink link:calculationLink 999021 - Disclosure - Operating Property (Tables) link:presentationLink link:definitionLink link:calculationLink 999022 - Disclosure - Leases (Tables) link:presentationLink link:definitionLink link:calculationLink 999023 - Disclosure - Share-Based Payment Arrangements (Tables) link:presentationLink link:definitionLink link:calculationLink 999024 - Disclosure - Segment Information (Tables) link:presentationLink link:definitionLink link:calculationLink 999025 - Disclosure - Change in Accounting Estimate for Self-Insured Claims (Tables) link:presentationLink link:definitionLink link:calculationLink 999026 - Disclosure - Significant Accounting Policies - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999027 - Disclosure - Schedule Of Revenue By Major Customers By Reporting Segments (Detail) link:presentationLink link:definitionLink link:calculationLink 999028 - Disclosure - Summary of Activity in Allowance for Doubtful Accounts (Detail) link:presentationLink link:definitionLink link:calculationLink 999029 - Disclosure - Other Comprehensive Income Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) link:presentationLink link:definitionLink link:calculationLink 999030 - Disclosure - Investments - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999031 - Disclosure - Amortized Cost and Fair Value of Available-for-Sale Investments (Detail) link:presentationLink link:definitionLink link:calculationLink 999032 - Disclosure - Schedule of Unrealized Loss on Available-for-Sale Investments (Detail) link:presentationLink link:definitionLink link:calculationLink 999033 - Disclosure - Schedule of Provision for Income Taxes (Detail) link:presentationLink link:definitionLink link:calculationLink 999034 - Disclosure - Income Taxes - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999035 - Disclosure - Schedule of Deferred Tax Assets and Liabilities (Detail) link:presentationLink link:definitionLink link:calculationLink 999036 - Disclosure - Schedule of Income Taxes Calculated on Income from Before Income Taxes and Provision for Income Taxes (Detail) link:presentationLink link:definitionLink link:calculationLink 999037 - Disclosure - Schedule for Gross Unrecognized Tax Benefits (Detail) link:presentationLink link:definitionLink link:calculationLink 999038 - Disclosure - Operating Property (Detail) link:presentationLink link:definitionLink link:calculationLink 999039 - Disclosure - Operating Property - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999040 - Disclosure - Retirement Plan - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999041 - Disclosure - Debt - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999042 - Disclosure - Leases - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999043 - Disclosure - Leases - Components of Lease Cost for Finance Leases and Operating Leases (Detail) link:presentationLink link:definitionLink link:calculationLink 999044 - Disclosure - Leases - Classification on our Consolidated Balance Sheet (Detail) link:presentationLink link:definitionLink link:calculationLink 999045 - Disclosure - Leases - Undiscounted Cash Flows for the Finance and Operating Leases (Detail) link:presentationLink link:definitionLink link:calculationLink 999046 - Disclosure - Leases - Undiscounted Cash Flows for the Finance and Operating Leases (Parenthetical) (Detail) link:presentationLink link:definitionLink link:calculationLink 999047 - Disclosure - Leases - Weighted Average Remaining Lease Term and the Weighted Average Discount Rate for Finance and Operating leases (Detail) link:presentationLink link:definitionLink link:calculationLink 999048 - Disclosure - Share-Based Payment Arrangements - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999049 - Disclosure - Amounts Recognized in Financial Statements with Respect to Plans (Detail) link:presentationLink link:definitionLink link:calculationLink 999050 - Disclosure - Schedule of Information on Restricted Stock Units (Detail) link:presentationLink link:definitionLink link:calculationLink 999051 - Disclosure - Schedule of Information on Non - Vested Restricted Stock Units (Detail) link:presentationLink link:definitionLink link:calculationLink 999052 - Disclosure - Summary of Information Regarding Stock Options (Detail) link:presentationLink link:definitionLink link:calculationLink 999053 - Disclosure - Equity - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999054 - Disclosure - Commitments and Contingencies - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999055 - Disclosure - Segment Information - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999056 - Disclosure - Information Regarding Reportable Business Segments (Detail) link:presentationLink link:definitionLink link:calculationLink 999057 - Disclosure - Effect of Increase in Cost of Insurance and Claims (Detail) link:presentationLink link:definitionLink link:calculationLink 999058 - Disclosure - Equity investment - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 999059 - Disclosure - Insider Trading Arrangements link:presentationLink link:definitionLink link:calculationLink