UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Total revenues	$ 1,363,086	$ 951,479	$ 3,888,507	$ 2,686,085
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	910,648	639,232	2,652,506	1,817,654
Selling, general and administrative expenses	151,711	133,164	458,492	378,911
Accretion of environmental liabilities	3,246	2,799	9,599	8,625
Depreciation and amortization	88,394	71,451	260,560	215,206
Income from operations	209,087	104,833	507,350	265,689
Other income (expense), net	104	199	2,073	(2,509)
Gain on sale of business	0	0	8,864	0
Interest expense, net of interest income of $1,103, $653, $2,159 and $1,712, respectively	(28,081)	(17,984)	(79,354)	(53,953)
Income before provision for income taxes	181,110	87,048	438,933	209,227
Provision for income taxes	45,311	21,605	109,663	54,973
Net income	$ 135,799	$ 65,443	$ 329,270	$ 154,254
Earnings per share:
Basic (in dollars per share)	$ 2.51	$ 1.20	$ 6.07	$ 2.83
Diluted (in dollars per share)	$ 2.50	$ 1.20	$ 6.04	$ 2.81
Shares used to compute earnings per share - Basic (in shares)	54,111	54,411	54,278	54,553
Shares used to compute earnings per share - Diluted (in shares)	54,381	54,707	54,542	54,862
Service revenues
Revenues:
Total revenues	$ 1,073,810	$ 744,549	$ 3,100,914	$ 2,141,820
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	738,041	508,498	2,168,025	1,451,498
Product revenues
Revenues:
Total revenues	289,276	206,930	787,593	544,265
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ 172,607	$ 130,734	$ 484,481	$ 366,156