CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Revenues	$ 333,081	$ 371,268	$ 667,894	$ 709,298
Cost of revenues	259,021	290,086	505,407	549,050
Research and development expenses	23,191	21,930	55,324	49,808
Selling, general and administrative expenses	24,563	33,160	49,750	60,501
Income from operations	26,306	26,092	57,413	49,939
Interest income and other	476	446	1,042	633
Interest expense	(1,184)	(2,970)	(2,294)	(6,047)
Income before income taxes	25,598	23,568	56,161	44,525
Income tax provision	(9,319)	(8,954)	(20,280)	(16,919)
Net income	16,279	14,614	35,881	27,606
Basic income per share:	$ 0.27	$ 0.25	$ 0.60	$ 0.47
Diluted income per share:	$ 0.27	$ 0.25	$ 0.59	$ 0.46
Net income	16,279	14,614	35,881	27,606
Other comprehensive income:
Defined benefit plans, net of tax of ($206), ($123), ($42) and $193, respectively	(329)	(200)	(67)	312
Unrealized gain on investments	300	500	600	800
Net gain (loss) on foreign exchange derivative instruments, net of tax of ($176), $0, $298 and $0, respectively	(282)	0	474	0
Total other comprehensive income	(311)	300	1,007	1,112
Comprehensive Income	$ 15,968	$ 14,914	$ 36,888	$ 28,718