CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS
Revenues	$ 1,601,762	$ 864,929	$ 598,302
Cost of revenues	1,088,115	663,262	480,739
Selling, general and administrative expenses	148,573	123,572	123,698
Pension settlement, impairment and other charges	2,921		217,493
Depreciation and amortization	83,017	72,686	95,530
Gain on disposition of assets, net	(8,804)	(10,882)	(9,523)
Operating income (loss)	287,940	16,291	(309,635)
Interest expense	(614)	(1,929)	(373)
Interest income	1,171	59	496
Other income, net	1,135	2,027	81
Income (loss) before income taxes	289,632	16,448	(309,431)
Income tax provision (benefit)	71,269	9,231	(97,239)
Net income (loss)	$ 218,363	$ 7,217	$ (212,192)
Earnings (loss) per share
Basic (in dollars per share)	$ 1.01	$ 0.03	$ (1.00)
Diluted (in dollars per share)	1.01	$ 0.03	$ (1.00)
Dividends paid per share (in dollars per share)	$ 0.04