UNAUDITED CONSOLIDATED STATEMENTS OF (LOSS) INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Service revenues	$ 760,667	$ 657,221	$ 2,158,344	$ 1,962,071
Product revenues	132,699	194,244	403,749	594,541
Total revenues	893,366	851,465	2,562,093	2,556,612
Cost of revenues (exclusive of items shown separately below)
Service revenues	523,676	440,261	1,484,936	1,333,443
Product revenues	110,970	158,146	348,905	497,633
Total cost of revenues	634,646	598,407	1,833,841	1,831,076
Selling, general and administrative expenses	93,113	99,701	321,246	334,394
Accretion of environmental liabilities	2,577	2,642	7,795	7,975
Depreciation and amortization	69,060	70,049	205,189	205,480
Goodwill impairment charge	0	123,414	31,992	123,414
Income (loss) from operations	93,970	(42,748)	162,030	54,273
Other (expense) income	(139)	613	(390)	4,136
Interest expense, net of interest income of $126, $174, $465 and $590, respectively	(19,017)	(19,494)	(57,704)	(58,430)
Income (loss) before provision for income taxes	74,814	(61,629)	103,936	(21)
Provision for income taxes	34,586	31,708	60,402	55,684
Net income (loss)	$ 40,228	$ (93,337)	$ 43,534	$ (55,705)
Earnings (loss) per share:
Basic (in USD per share)	$ 0.69	$ (1.55)	$ 0.74	$ (0.92)
Diluted (in USD per share)	$ 0.69	$ (1.55)	$ 0.74	$ (0.92)
Shares used to compute earnings (loss) per share - Basic	58,161	60,369	58,799	60,585
Shares used to compute earnings (loss) per share - Diluted	58,268	60,369	58,898	60,585