Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Cash Flows [Abstract]
Net Income	$ 771,118	$ 743,748	$ 410,635
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment, and intangibles	659,824	577,895	506,670
Gain on sale of property and equipment	(92,891)	(74,799)	(9,706)
Impairments	810	299	5,335
Deferred income taxes	30,852	39,929	46,214
Non-cash lease expense	41,943	45,192	80,891
Loss (gain) on equity securities	52,274	(3,931)	(3,737)
Non-cash adjustment to fair value of convertible note	0	(12,631)	0
Other adjustments to reconcile net income to net cash provided by operating activities	46,632	44,841	47,419
Increase (decrease) in cash resulting from changes in:
Trade receivables	58,708	(214,573)	(75,521)
Income tax receivable	(58,065)	2,528	14,123
Accounts payable	(24,769)	73,371	7,500
Accrued liabilities and claims accrual	11,151	40,872	(31,210)
Operating lease liabilities	(42,893)	(48,171)	(83,675)
Other assets and liabilities	(18,841)	(24,417)	4,707
Net cash provided by operating activities	1,435,853	1,190,153	919,645
Cash flows from investing activities:
Proceeds from maturities of held-to-maturity investments	9,706	10,624	13,675
Purchases of held-to-maturity investments	(11,145)	(7,706)	(16,936)
Proceeds from sale of property and equipment, including assets held for sale	183,421	252,080	133,230
Purchases of property and equipment	(800,563)	(534,096)	(521,067)
Expenditures on assets held for sale	(545)	(1,367)	(483)
Net cash, restricted cash, and equivalents invested in acquisitions	(31,291)	(1,496,208)	(46,811)
Investment in convertible note	0	(35,000)	0
Other cash flows from investing activities	4,233	(5,060)	(42,320)
Net cash used in investing activities	(646,184)	(1,816,733)	(480,712)
Cash flows from financing activities:
Repayment of finance leases and long-term debt	(274,833)	(409,889)	(148,910)
Proceeds from long-term debt	0	1,200,000	0
(Repayments) borrowings on revolving lines of credit, net	(217,000)	50,000	(69,000)
Borrowings under accounts receivable securitization	140,000	80,000	61,000
Repayment of accounts receivable securitization	0	(15,000)	(52,000)
Proceeds from common stock issued	7,432	9,282	12,748
Repurchases of the Company's common stock	(299,941)	(57,175)	(179,585)
Dividends paid	(78,304)	(63,535)	(54,620)
Other cash flows from financing activities	(31,701)	(14,357)	(13,517)
Net cash (used in) provided by financing activities	(754,347)	779,326	(443,884)
Net increase (decrease) in cash, restricted cash, and equivalents	35,322	152,746	(4,951)
Cash, restricted cash, and equivalents at beginning of period	350,023	197,277	202,228
Cash, restricted cash, and equivalents at end of period	385,345	350,023	197,277
Cash paid during the period for:
Interest	48,905	18,949	17,396
Income taxes	289,159	167,092	80,006
Other Significant Noncash Transactions [Line Items]
Equipment acquired included in accounts payable	34,909	10,489	651
Purchase price adjustment on acquisition	2,164	0	0
Contingent consideration associated with acquisitions and investments	1,717	6,250	16,200
Value of common stock issued for acquisition	0	10,000	0
Conversion of note receivable to equity investment	0	37,631	0
Right-of-use assets obtained in exchange for operating lease liabilities	86,910	22,771	12,406
Property and equipment obtained in exchange for finance lease liabilities	152,509	181,234	137,097
Transfers from property and equipment to assets held for sale [Member]
Other Significant Noncash Transactions [Line Items]
Other non-cash investing and financing activities	90,951	92,445	75,292
Noncontrolling Interest Associated With Acquisition
Other Significant Noncash Transactions [Line Items]
Other non-cash investing and financing activities	0	10,281	0
Property and equipment obtained in exchange for finance lease liabilities from operating lease liabilities
Other Significant Noncash Transactions [Line Items]
Property and equipment obtained in exchange for finance lease liabilities	6,462	42,298	67,430
Acquisitions
Other Significant Noncash Transactions [Line Items]
Right-of-use assets obtained in exchange for operating lease liabilities through acquisitions	$ 0	$ 50,988	$ 12,356