Condensed Consolidated Statement of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2011	$ 129,391	$ 564	$ 47,701	$ 81,101	$ 25
Balance (in shares) at Dec. 31, 2011	56,397	56,397
Comprehensive income:
Net income	65,599	0	0	65,599	0
Unrealized loss on available-for-sale marketable debt securities	(6)	0	0	0	(6)
Total comprehensive income	65,593
Exercise of common stock options	3,279	4	3,275	0	0
Exercise of common stock options (in shares)		399
Tax effect from stock-based compensation	4,802	0	4,802	0	0
Stock-based compensation	9,570	2	9,568	0	0
Stock-based compensation (in shares)		169
Repurchases of common stock	(24,071)	(10)	(24,061)	0	0
Repurchases of common stock (in shares)		(925)
Balance at Sep. 29, 2012	$ 188,564	$ 560	$ 41,285	$ 146,700	$ 19
Balance (in shares) at Sep. 29, 2012	56,040	56,040