CONDENSED CONSOLIDATED INCOME STATEMENTS AND STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
CONDENSED CONSOLIDATED INCOME STATEMENTS (Unaudited) [Abstract]
Revenues	$ 372,882	$ 342,170	$ 1,082,180	$ 1,010,472
Cost of revenues	284,288	267,494	833,338	821,292
Research and development expenses	32,913	26,681	82,721	67,248
Selling, general and administrative expenses	24,368	23,327	84,869	64,340
Income from operations	31,313	24,668	81,252	57,592
Interest income and other	61	369	694	12,561
Interest expense	(2,517)	(2,880)	(8,564)	(8,217)
Income before income taxes	28,857	22,157	73,382	61,936
Income tax provision	(9,405)	(5,684)	(26,323)	(11,912)
Net income	19,452	16,473	47,059	50,024
Basic income per share	$ 0.33	$ 0.28	$ 0.79	$ 0.85
Diluted income per share	$ 0.33	$ 0.28	$ 0.79	$ 0.84
Net Income (from above)	19,452	16,473	47,059	50,024
Other comprehensive income
Unrealized gain on investments	100	0	900	1,100
Defined benefit plans, net of tax	190	(958)	502	(1,085)
Foreign currency translation adjustment, net of tax	(131)	0	(131)	0
Total other comprehensive income (loss)	159	(958)	1,271	15
Comprehensive Income	$ 19,611	$ 15,515	$ 48,330	$ 50,039