UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Service revenues	$ 560,214	$ 530,231
Product revenues	128,727	105,852
Total revenues	688,941	636,083
Cost of revenues (exclusive of items shown separately below)
Service revenues	391,087	373,986
Product revenues	105,498	90,293
Total cost of revenues	496,585	464,279
Selling, general and administrative expenses	112,221	104,484
Accretion of environmental liabilities	2,290	2,505
Depreciation and amortization	72,412	68,902
(Loss) income from operations	5,433	(4,087)
Other expense	(1,549)	(350)
Interest expense, net of interest income of $215 and $150, respectively	(22,576)	(18,980)
(Loss) income before (benefit) provision for income taxes	(18,692)	(23,417)
Provision (benefit) for income taxes	2,701	(2,546)
Net loss	$ (21,393)	$ (20,871)
Loss per share:
Basic (in USD per share)	$ (0.37)	$ (0.36)
Diluted (in USD per share)	$ (0.37)	$ (0.36)
Shares used to compute loss per share - Basic (in shares)	57,262	57,617
Shares used to compute loss per share - Diluted (in shares)	57,262	57,617