CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CONSOLIDATED STATEMENTS OF OPERATIONS
Revenues	$ 864,929	$ 598,302	$ 1,222,409
Cost of revenues (exclusive of items shown below)	663,262	480,739	919,595
Selling, general and administrative expenses	123,572	123,698	168,127
Impairment and other charges		217,493	82,273
Depreciation and amortization	72,686	95,530	170,409
Gain on disposition of assets, net	(10,882)	(9,523)	(3,707)
Operating income (loss)	16,291	(309,635)	(114,288)
Interest expense	(1,929)	(373)	(334)
Interest income	59	496	1,906
Other income (expense), net	2,027	81	(385)
Income (loss) before income taxes	16,448	(309,431)	(113,101)
Income tax provision (benefit)	9,231	(97,239)	(25,990)
Net income (loss)	$ 7,217	$ (212,192)	$ (87,111)
Earnings (loss) per share
Basic (in dollars per share)	$ 0.03	$ (1.00)	$ (0.41)
Diluted (in dollars per share)	$ 0.03	$ (1.00)	(0.41)
Dividends paid per share (in dollars per share)			$ 0.15