UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Total revenues	$ 858,563	$ 780,839
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	606,666	564,364
Selling, general and administrative expenses	129,307	114,812
Accretion of environmental liabilities	2,561	2,574
Depreciation and amortization	74,533	75,355
Income from operations	45,496	23,734
Other (expense) income, net	(2,365)	2,983
Loss on sale of businesses	(3,074)	0
Interest expense, net of interest income of $998 and $926, respectively	(18,787)	(19,764)
Income before provision for income taxes	21,270	6,953
Provision for income taxes	9,698	5,977
Net income	$ 11,572	$ 976
Earnings per share:
Basic (in USD per share)	$ 0.21	$ 0.02
Diluted (in USD per share)	$ 0.21	$ 0.02
Shares used to compute earnings per share - Basic (in shares)	55,757	55,848
Shares used to compute earnings per share - Diluted (in shares)	56,055	56,082
Service
Revenues:
Total revenues	$ 719,867	$ 656,658
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	492,716	463,483
Product
Revenues:
Total revenues	138,696	124,181
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ 113,950	$ 100,881