Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Balance at Dec. 28, 2012	$ 216,429	$ 33	$ 123,676	$ (250)	$ 206,057	$ (113,087)
Balance (in shares) at Dec. 28, 2012		32,853				6,442
Employee stock purchase plan	1,166	$ 0	648	0	0	$ 518
Employee stock purchase plan (in shares)		0				(38)
Exercise of stock options, net of swaps	294	$ 0	(302)	0	(1,031)	$ 1,627
Exercise of stock options, net of swaps (in shares)		0				(122)
Excess tax benefit for equity incentive plans	4,267	$ 0	4,267	0	0	$ 0
Amortization of unrecognized stock-based compensation	7,107	0	7,107	0	0	0
Purchase of treasury shares	(25,011)	$ 0	0	0		$ (25,011)
Purchase of treasury shares (in shares)		0				876
Foreign currency translation adjustments	373	$ 0	0	373	0	$ 0
Grant of restricted stock units to settle accrued bonus	5,807	0	5,807	0	0	0
Settlement of restricted stock units	(6,028)	$ 0	(273)	0	(9,352)	$ 3,597
Settlement of restricted stock units (in shares)		0				(431)
Unrealized gain (loss) on investments	(14)	$ 0	0	(14)	0	$ 0
Dividends and dividend equivalent rights	(7,971)	0	303	0	(8,274)	0
Net income	38,640	0	0	0	38,640	0
Balance at Jan. 03, 2014	235,059	$ 33	141,233	109	226,040	$ (132,356)
Balance (in shares) at Jan. 03, 2014		32,853				6,727
Employee stock purchase plan	1,147	$ 0	810	0	0	$ 337
Employee stock purchase plan (in shares)		0				(32)
Exercise of stock options, net of swaps	960	$ 0	67	0	0	$ 893
Exercise of stock options, net of swaps (in shares)		0				(84)
Excess tax benefit for equity incentive plans	5,100	$ 0	5,100	0	0	$ 0
Amortization of unrecognized stock-based compensation	6,792	0	6,792	0	0	0
Purchase of treasury shares	(30,921)	$ 0	0	0		$ (30,921)
Purchase of treasury shares (in shares)		0				850
Foreign currency translation adjustments	(1,017)	$ 0	0	(1,017)	0	$ 0
Grant of restricted stock units to settle accrued bonus	6,008	0	6,008	0	0	0
Settlement of restricted stock units	(6,356)	$ 0	(343)	0	(6,050)	$ 37
Settlement of restricted stock units (in shares)		0				(350)
Unrealized gain (loss) on investments	4	$ 0	0	4	0	$ 0
Dividends and dividend equivalent rights	(13,189)	0	541	0	(13,730)	0
Net income	40,701	0	0	0	40,701	0
Balance at Jan. 02, 2015	244,288	$ 33	160,208	(904)	246,961	$ (162,010)
Balance (in shares) at Jan. 02, 2015		32,853				7,111
Employee stock purchase plan	1,186	$ 0	836	0	0	$ 350
Employee stock purchase plan (in shares)		0				(27)
Exercise of stock options, net of swaps	1,828	$ 0	(94)	0	0	$ 1,922
Exercise of stock options, net of swaps (in shares)		0				(150)
Excess tax benefit for equity incentive plans	6,396	$ 0	6,396	0	0	$ 0
Amortization of unrecognized stock-based compensation	6,618	0	6,618	0	0	0
Purchase of treasury shares	(23,314)	$ 0	0	0		$ (23,314)
Purchase of treasury shares (in shares)		0				530
Foreign currency translation adjustments	(822)	$ 0	0	(822)	0	$ 0
Grant of restricted stock units to settle accrued bonus	6,169	0	6,169	0	0	0
Settlement of restricted stock units	(7,365)	$ 0	(975)	0	(4,943)	$ (1,447)
Settlement of restricted stock units (in shares)		0				(331)
Unrealized gain (loss) on investments	(79)	$ 0	0	(79)	0	$ 0
Dividends and dividend equivalent rights	(15,700)	0	658	0	(16,358)	0
Net income	43,599	0	0	0	43,599	0
Balance at Jan. 01, 2016	$ 262,804	$ 33	$ 179,816	$ (1,805)	$ 269,259	$ (184,499)
Balance (in shares) at Jan. 01, 2016		32,853				7,133