Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Operations [Abstract]
Revenues	$ 958,180	$ 715,954	$ 490,275
Cost of revenues	744,176	576,920	447,624
Selling, general and administrative expenses	81,672	64,157	61,205
Other operating income, net	(432)	(3,127)	(3,229)
Operating income (loss)	132,764	78,004	(15,325)
Foreign currency exchange loss (gain)	522	(1,134)	(1,870)
Interest expense, net	9,226	10,267	9,334
Income (loss) from operations before income taxes	123,016	68,871	(22,789)
Provision for income taxes	42,999	27,245	(2,216)
Net income (loss)	$ 80,017	$ 41,626	$ (20,573)
Income (loss) per common share -basic:	$ 0.89	$ 0.47	$ (0.23)
Income (loss) per common share -diluted:	$ 0.80	$ 0.46	$ (0.23)