Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Revenues	$ 230,822	$ 181,352	$ 433,473	$ 342,150
Cost of revenues	178,911	145,299	337,913	278,817
Selling, general and administrative expenses	21,150	16,360	36,968	30,773
Other operating income, net	(835)	(203)	(952)	(1,045)
Operating income	31,596	19,896	59,544	33,605
Foreign currency exchange gain	(468)	(1,213)	(145)	(1,824)
Interest expense, net	2,100	2,228	4,357	4,376
Income from operations before income taxes	29,964	18,881	55,332	31,053
Provision for income taxes	10,684	8,041	20,198	12,431
Net income	$ 19,280	$ 10,840	$ 35,134	$ 18,622
Income per common share - basic	$ 0.21	$ 0.12	$ 0.39	$ 0.21
Income per common share - diluted	$ 0.19	$ 0.12	$ 0.35	$ 0.21