Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	$ 285,708	$ 259,599	$ 844,848	$ 767,691
Cost of revenues	230,206	210,276	685,856	626,712
Selling, general and administrative expenses	25,433	20,878	74,277	62,135
Other operating income, net	(232)	(311)	(872)	(802)
Operating income	30,301	28,756	85,587	79,646
Foreign currency exchange loss	975	185	1,082	416
Interest expense, net	2,728	2,416	8,050	7,337
Income from operations before income taxes	26,598	26,155	76,455	71,893
Provision for income taxes	7,838	7,413	24,656	23,054
Net income	$ 18,760	$ 18,742	$ 51,799	$ 48,839
Income per common share -basic: (in Dollars per share)	$ 0.22	$ 0.22	$ 0.61	$ 0.55
Income per common share -diluted: (in Dollars per share)	$ 0.20	$ 0.20	$ 0.54	$ 0.50