CONSOLIDATED INCOME STATEMENTS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONSOLIDATED INCOME STATEMENTS [Abstract]
Revenues	$ 1,345,923	$ 1,294,577	$ 1,125,295
Cost of revenues	1,074,389	1,007,668	890,313
Research and development expenses	102,751	122,270	109,754
Selling, general and administrative expenses	88,989	91,625	72,935
Income from operations	79,794	73,014	52,293
Interest income and other	19,335	1,848	4,968
Interest expense	(11,096)	(9,778)	(9,039)
Income before income taxes	88,033	65,084	48,222
Income tax provision	(20,639)	(17,615)	(11,615)
Net income	$ 67,394	$ 47,469	$ 36,607
Basic income per share:
Basic income per share:	$ 1.14	$ 0.81	$ 0.64
Net income (in dollars per share)	$ 1.14	$ 0.81	$ 0.64
Diluted income per share:
Diluted income per share:	$ 1.13	$ 0.81	$ 0.63
Net income (in dollars per share)	$ 1.13	$ 0.81	$ 0.63