CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF OPERATIONS
Revenues	$ 1,617,474	$ 1,601,762	$ 864,929
Cost of revenues (exclusive of depreciation and amortization shown separately below)	1,089,519	1,088,115	663,262
Selling, general and administrative expenses	165,940	148,573	123,572
Pension settlement charges	18,286	2,921
Depreciation and amortization	108,123	83,017	72,686
Gain on disposition of assets, net	(9,344)	(8,804)	(10,882)
Operating income	244,950	287,940	16,291
Interest expense	(341)	(614)	(1,929)
Interest income	8,599	1,171	59
Other income, net	3,035	1,135	2,027
Income before income taxes	256,243	289,632	16,448
Income tax provision	61,130	71,269	9,231
Net income	$ 195,113	$ 218,363	$ 7,217
Earnings per share
Basic (in dollars per share)	$ 0.90	$ 1.01	$ 0.03
Diluted (in dollars per share)	0.90	1.01	$ 0.03
Dividends paid per share (in dollars per share)	$ 0.16	$ 0.04