UNAUDITED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Service revenues	$ 672,622	$ 534,311
Product revenues	189,541	37,711
Total revenues	862,163	572,022
Cost of revenues (exclusive of items shown separately below)
Service revenues	468,372	369,125
Product revenues	167,652	31,190
Total cost of revenues	636,024	400,315
Selling, general and administrative expenses	128,470	70,759
Accretion of environmental liabilities	2,835	2,416
Depreciation and amortization	60,006	36,831
Income from operations	34,828	61,701
Other income (expense)	525	(299)
Interest expense, net of interest income of $111 and $186, respectively	(19,873)	(11,272)
Income before provision for income taxes	15,480	50,130
Provision for income taxes	4,978	18,115
Net income	$ 10,502	$ 32,015
Earnings per share:
Basic	$ 0.17	$ 0.60
Diluted	$ 0.17	$ 0.60
Weighted average common shares outstanding - basic	60,464	53,227
Weighted average common shares outstanding - diluted	60,630	53,488