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. 28, 2013	$ 225,220	$ 549	$ 5,382	$ 219,276	$ 13
Balance (in shares) at Dec. 28, 2013	54,901	54,901
Net income	25,473	0	0	25,473	0
Other comprehensive income:
Unrealized gain on available-for-sale marketable debt securities, net of tax	30	0	0	0	30
Exercise of common stock options	1,366	0	1,366	0	0
Exercise of common stock options (in shares)		101
Tax effect from stock-based compensation	313	0	313	0	0
Stock-based compensation	2,035	0	2,035	0	0
Stock-based compensation (in shares)		(84)
Repurchases of common stock	(21,470)	(12)	(9,096)	(12,362)	0
Repurchases of common stock (in shares)		(1,175)
Balance at Jun. 28, 2014	$ 232,967	$ 537	$ 0	$ 232,387	$ 43
Balance (in shares) at Jun. 28, 2014	53,743	53,743