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 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 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
Employee stock purchase plan	1,190	$ 0	883	0	0	$ 307
Employee stock purchase plan (in shares)		0				(23)
Exercise of stock options, net of swaps	566	$ 0	161	0	0	$ 405
Exercise of stock options, net of swaps (in shares)		0				(30)
Amortization of unrecognized stock-based compensation	7,152	$ 0	7,152	0	0	$ 0
Purchase of treasury shares	(24,456)	$ 0	0	0		$ (24,456)
Purchase of treasury shares (in shares)		0				491
Foreign currency translation adjustments	(1,240)	$ 0	0	(1,240)	0	$ 0
Grant of restricted stock units to settle accrued bonus	6,334	0	6,334	0	0	0
Settlement of restricted stock units	(7,685)	$ 0	(701)	0	(5,791)	$ (1,193)
Settlement of restricted stock units (in shares)		0				(315)
Unrealized loss on investments	(81)	$ 0	0	(81)	0	$ 0
Dividends and dividend equivalent rights	(18,773)	0	854	0	(19,627)	0
Other	55	0	133	0	(78)	0
Net income	47,480	0	0	0	47,480	0
Balance at Dec. 30, 2016	273,346	$ 33	194,632	(3,126)	291,243	$ (209,436)
Balance (in shares) at Dec. 30, 2016		32,853				7,256
Employee stock purchase plan	1,207	$ 0	847	0	0	$ 360
Employee stock purchase plan (in shares)		0				(20)
Exercise of stock options, net of swaps	818	$ 0	144	0	0	$ 674
Exercise of stock options, net of swaps (in shares)		0				(35)
Amortization of unrecognized stock-based compensation	7,824	$ 0	7,824	0	0	$ 0
Purchase of treasury shares	(11,931)	$ 0	0	0		$ (11,931)
Purchase of treasury shares (in shares)		0				186
Foreign currency translation adjustments	1,187	$ 0	0	1,187	0	$ 0
Grant of restricted stock units to settle accrued bonus	6,918	0	6,918	0	0	0
Settlement of restricted stock units	(9,520)	$ 0	(1,017)	0	(5,667)	$ (2,836)
Settlement of restricted stock units (in shares)		0				(303)
Unrealized loss on investments	(90)	$ 0	0	(90)	0	$ 0
Dividends and dividend equivalent rights	(21,976)	0	915	0	(22,891)	0
Net income	41,305	0	0	0	41,305	0
Balance at Dec. 29, 2017	$ 289,088	$ 33	$ 210,263	$ (2,029)	$ 303,990	$ (223,169)
Balance (in shares) at Dec. 29, 2017		32,853				7,084