Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income	$ 76,097	$ 79,424
Noncash items included in net income:
Depreciation and amortization	42,880	39,952
Deferred income taxes	5,738	(2,030)
Other, net	2,968	181
Changes in operating assets and liabilities:
Accounts receivable	(5,276)	(46,831)
Accounts payable	7,008	28,118
Change in other assets, liabilities, net	(10,145)	(2,853)
Net cash provided by operating activities	119,270	95,961
Investing Activities:
Acquisition of property and equipment	(128,415)	(46,259)
Proceeds from disposal of property and equipment	360	883
Net cash used in investing activities	(128,055)	(45,376)
Financing Activities:
Proceeds from stock option exercises	2,204	907
Shares withheld for taxes	(8,927)	(11,230)
Repayment of finance leases	(4,504)	(5,525)
Other financing activity	(953)
Net cash used in financing activities	(12,180)	(15,848)
Net Increase (Decrease) in Cash and Cash Equivalents	(20,965)	34,737
Cash and Cash Equivalents, beginning of period	187,390	106,588
Cash and Cash Equivalents, end of period	$ 166,425	$ 141,325