UNAUDITED CONSOLIDATED STATEMENTS OF (LOSS) INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues:
Service revenues	$ 801,347	$ 665,275	$ 1,397,677	$ 1,325,370
Product revenues	134,881	193,205	271,050	379,777
Total revenues	936,228	858,480	1,668,727	1,705,147
Cost of revenues (exclusive of items shown separately below)
Service revenues	544,870	445,757	961,260	912,556
Product revenues	107,818	161,193	237,935	320,113
Total cost of revenues	652,688	606,950	1,199,195	1,232,669
Selling, general and administrative expenses	120,418	115,731	228,133	234,693
Accretion of environmental liabilities	2,599	2,609	5,218	5,333
Depreciation and amortization	67,773	66,075	136,129	135,431
Goodwill impairment charge	31,992	0	31,992	0
Income from operations	60,758	67,115	68,060	97,021
Other (expense) income	(660)	(655)	(251)	3,523
Interest expense, net of interest income of $188, $211, $339 and $416, respectively	(19,249)	(19,382)	(38,687)	(38,936)
Income before provision for income taxes	40,849	47,078	29,122	61,608
Provision for income taxes	30,454	18,406	25,816	23,976
Net income	$ 10,395	$ 28,672	$ 3,306	$ 37,632
Earnings per share:
Basic (in USD per share)	$ 0.18	$ 0.47	$ 0.06	$ 0.62
Diluted (in USD per share)	$ 0.18	$ 0.47	$ 0.06	$ 0.62
Shares used to compute earnings per share - Basic	58,590	60,665	58,732	60,695
Shares used to compute earnings per share - Diluted	58,710	60,778	58,832	60,822