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 Jan. 01, 2011	$ 57,977	$ 555	$ 36,799	$ 20,623	$ 0
Balance (in shares) at Jan. 01, 2011		55,455
Comprehensive income:
Net income	60,478	0	0	60,478	0
Unrealized gain (loss) on available-for-sale marketable debt securities	25	0	0	0	25
Exercise of common stock options	4,356	7	4,349	0	0
Exercise of common stock options (in shares)		725
Tax effect from stock-based compensation	1,865	0	1,865	0	0
Stock-based compensation	4,971	2	4,969	0	0
Stock-based compensation (in shares)		204
Repurchases of common stock	(371)	0	(371)	0	0
Repurchases of common stock (in shares)		(30)
Other	90	0	90	0	0
Other (shares)	43
Balance at Dec. 31, 2011	129,391	564	47,701	81,101	25
Balance (in shares) at Dec. 31, 2011		56,397
Comprehensive income:
Net income	78,094	0	0	78,094	0
Unrealized gain (loss) on available-for-sale marketable debt securities	(5)	0	0	0	(5)
Exercise of common stock options	5,138	7	5,131	0	0
Exercise of common stock options (in shares)		659
Tax effect from stock-based compensation	5,665	0	5,665	0	0
Stock-based compensation	10,306	1	10,305	0	0
Stock-based compensation (in shares)		170
Repurchases of common stock	(34,892)	(13)	(34,879)	0	0
Repurchases of common stock (in shares)		(1,323)
Balance at Dec. 29, 2012	193,697	559	33,923	159,195	20
Balance (in shares) at Dec. 29, 2012	55,903	55,903
Comprehensive income:
Net income	60,081	0	0	60,081	0
Unrealized gain (loss) on available-for-sale marketable debt securities	(7)	0	0	0	(7)
Exercise of common stock options	7,966	7	7,959	0	0
Exercise of common stock options (in shares)		757
Tax effect from stock-based compensation	1,007	0	1,007	0	0
Stock-based compensation	4,232	2	4,230	0	0
Stock-based compensation (in shares)		160
Repurchases of common stock	(42,072)	(19)	(42,053)	0	0
Repurchases of common stock (in shares)		(1,919)
Other	316	0	316	0	0
Other (shares)	0
Balance at Dec. 28, 2013	$ 225,220	$ 549	$ 5,382	$ 219,276	$ 13
Balance (in shares) at Dec. 28, 2013	54,901	54,901