CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net Income (Loss)	$ 108,285	$ 190,349
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	91,474	71,922
Impairment of right-of-use asset	2,012	0
Deferred taxes	10,837	3,279
Compensation expense related to share-based compensation plans	10,615	10,237
Gain on sale of assets	(4,834)	(12,509)
Changes in operating assets and liabilities:
Restricted investments	(2,197)	5,200
Accounts receivable, net	103,270	(93,767)
Prepaid taxes	1,729	(2,166)
Prepaid expenses and other current assets	17,469	9,664
Other assets	(1,899)	(2,517)
Accounts payable	(55,085)	3,380
Accrued expenses	(47,700)	23,251
Non-current liabilities	(12,595)	(5,588)
Net cash provided by operating activities	221,381	200,735
Cash flows from investing activities:
Proceeds from sale of equipment	15,135	18,584
Purchases of property and equipment	(65,635)	(85,942)
Cash used in acquisition	108	0
Net cash used in investing activities	(50,392)	(67,358)
Cash flows from financing activities:
Purchase of treasury stock	(100,026)	0
Repayments of long-term debt	(56,191)	(54,114)
Stock withheld for payments of withholding taxes	(7,818)	(5,715)
Finance lease payments	(1,501)	(1,059)
Proceeds from issuance of debt	50,289	66,194
Net cash (used in) provided by financing activities	(115,247)	5,306
Effect of exchange rate changes on cash and cash equivalents	45	9
Net increase in cash and cash equivalents	55,787	138,692
Cash and cash equivalents beginning of the period	286,642	159,784
Cash and cash equivalents end of the period	342,429	298,476
Supplemental disclosures of cash paid for:
Interest	6,688	3,710
Income taxes	$ 14,410	$ 58,082