CONDENSED CONSOLIDATED INCOME STATEMENTS AND STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CONDENSED CONSOLIDATED INCOME STATEMENTS (Unaudited) [Abstract]
Revenues	$ 338,030	$ 317,703
Cost of revenues	258,964	271,040
Research and development expenses	27,878	17,135
Selling, general and administrative expenses	27,342	19,412
Income from operations	23,846	10,116
Interest income and other	188	11,489
Interest expense	(3,077)	(2,533)
Income before income taxes	20,957	19,072
Income tax provision	(7,964)	(6,737)
Net income	12,993	12,335
Basic income per share (in dollars per share)	$ 0.22	$ 0.21
Diluted income per share (in dollars per share)	$ 0.22	$ 0.21
Net Income (from above)	12,993	12,335
Other comprehensive income
Unrealized gain on investments	300	600
Defined benefit plans, net of tax	512	29
Total other comprehensive income	812	629
Comprehensive Income	$ 13,805	$ 12,964