UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenues:
Total revenues	$ 1,549,337	$ 1,529,422	$ 4,531,141	$ 4,458,836
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	1,048,490	1,055,599	3,103,871	3,062,211
Selling, general and administrative expenses	189,610	177,846	558,640	557,590
Accretion of environmental liabilities	3,499	3,618	10,710	10,139
Depreciation and amortization	114,729	100,063	342,994	295,632
Income from operations	193,009	192,296	514,926	533,264
Other income (expense), net	3,517	(1,123)	1,982	(2,431)
Interest expense, net of interest income of $6,497, $5,391, $17,212 and $13,257, respectively	(35,700)	(35,779)	(108,883)	(100,767)
Income before provision for income taxes	160,826	155,394	408,025	430,066
Provision for income taxes	42,027	40,181	103,641	111,741
Net income	$ 118,799	$ 115,213	$ 304,384	$ 318,325
Earnings per share:
Basic (in dollars per share)	$ 2.22	$ 2.14	$ 5.67	$ 5.90
Diluted (in dollars per share)	$ 2.21	$ 2.12	$ 5.65	$ 5.87
Shares used to compute earnings per share - Basic (in shares)	53,518	53,951	53,659	53,936
Shares used to compute earnings per share - Diluted (in shares)	53,713	54,229	53,871	54,229
Service revenues
Revenues:
Total revenues	$ 1,321,865	$ 1,278,955	$ 3,860,267	$ 3,719,183
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	873,744	872,829	2,588,407	2,539,569
Product revenues
Revenues:
Total revenues	227,472	250,467	670,874	739,653
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ 174,746	$ 182,770	$ 515,464	$ 522,642