Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net income	$ 357,422	$ 253,235	$ 138,340
Noncash items included in net income:
Depreciation and amortization	157,203	141,700	134,655
Provision for doubtful accounts	3,074	3,559	4,271
Deferred income taxes	21,634	4,319	8,263
Loss (gain) from property disposals, net	50	(3,894)	(2,528)
Stock-based compensation	8,827	8,703	7,536
Changes in operating assets and liabilities:
Accounts receivable	(16,624)	(63,415)	(25,051)
Accounts payable	(9,523)	16,729	5,772
Other, net	(49,037)	(21,656)	37,887
Net cash provided by operating activities	473,026	382,592	309,145
Investing Activities:
Acquisition of property and equipment	(367,429)	(285,746)	(231,142)
Proceeds from disposal of property and equipment	1,917	8,398	12,325
Investment in equity securities	0	(500)	0
Net cash used in investing activities	(365,512)	(277,848)	(218,817)
Financing Activities:
Repayment of revolving credit agreement	(1,000)	(43,175)	(369,001)
Borrowing of revolving credit agreement	1,000	43,175	323,072
Proceeds from stock option exercises	4,511	3,678	3,786
Shares withheld for taxes	(11,752)	(6,571)	(3,600)
Repayment of finance leases	(19,471)	(20,571)	(19,525)
Net cash used in financing activities	(26,712)	(23,464)	(65,268)
Net Increase in Cash and Cash Equivalents	80,802	81,280	25,060
Cash and cash equivalents, beginning of year	106,588	25,308	248
Cash and cash equivalents, end of year	$ 187,390	$ 106,588	$ 25,308