Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Consolidated Statements of Operations [Abstract]
NET REVENUES	$ 259,025		$ 297,366		$ 218,887
COST OF REVENUES	115,881	[1]	128,535	[1]	105,134	[1]
GROSS PROFIT	143,144		168,831		113,753
OPERATING EXPENSES:
Research and development	49,952	[1]	46,271	[1]	46,522	[1]
Selling, general and administrative	46,415	[1]	47,590	[1]	37,325	[1]
Proxy contest credits	0		0		(550)
Equipment impairment and restructuring charges	0		0		6,514
Total operating expenses	96,367		93,861		89,811
INCOME FROM OPERATIONS	46,777		74,970		23,942
OTHER INCOME:
Interest income	703		566		828
Interest expense	(19)		(223)		(272)
Other income	141		149		132
Total other income, net	825		492		688
INCOME BEFORE INCOME TAXES	47,602		75,462		24,630
PROVISION FOR INCOME TAXES	13,586		24,754		8,336
NET INCOME	$ 34,016		$ 50,708		$ 16,294
NET INCOME PER SHARE:
Basic	$ 0.55		$ 0.82		$ 0.26
Diluted	$ 0.55		$ 0.81		$ 0.26
WEIGHTED-AVERAGE SHARES USED IN COMPUTING PER SHARE AMOUNTS:
Basic	61,609		62,030		63,576
Diluted	62,371		62,557		63,644
Cash dividends per common share	$ 0.15		$ 0.14		$ 0.14

[1] Share-based compensation included in: