Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock, At Cost [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning balance at Jan. 25, 2009	$ 784	$ 338,603	$ 333,747	$ (295,844)	$ 730	$ 378,020
Beginning balance, Shares at Jan. 25, 2009	60,287,427
Comprehensive income:
Net income			957			957
Change in net unrealized holding gain on available-for-sale investments					83	83
Translation adjustment					5	5
Comprehensive income						1,045
Acquisition consideration, exchanged options		458				458
Stock-based compensation		18,977				18,977
Repurchase of outstanding common stock				(2,931)		(2,931)
Repurchase of outstanding common stock, Shares	(206,350)					(206,350)
Treasury stock reissued		(8,181)		19,469		11,288
Treasury stock reissued, Shares	1,154,938
Shares issued under equity award plans, Shares	25,000
Tax benefit from stock based compensation		(1,116)				(1,116)
Ending balance at Jan. 31, 2010	784	348,741	334,704	(279,306)	818	405,741
Ending balance, Shares at Jan. 31, 2010	61,261,015
Comprehensive income:
Net income			72,572			72,572
Change in net unrealized holding gain on available-for-sale investments					(76)	(76)
Translation adjustment					1	1
Comprehensive income						72,497
Stock-based compensation		24,204				24,204
Repurchase of outstanding common stock				(2,819)		(2,819)
Repurchase of outstanding common stock, Shares	(164,636)					(164,636)
Treasury stock reissued		(19,169)		49,858		30,689
Treasury stock reissued, Shares	2,825,111
Shares issued under equity award plans	1					1
Shares issued under equity award plans, Shares	6,250
Tax benefit from stock based compensation		(1,698)				(1,698)
Ending balance at Jan. 30, 2011	785	352,078	407,276	(232,267)	743	528,615
Ending balance, Shares at Jan. 30, 2011	63,927,740					63,927,740
Comprehensive income:
Net income			89,087			89,087
Change in net unrealized holding gain on available-for-sale investments					(204)	(204)
Translation adjustment					(4)	(4)
Comprehensive income						88,879
Stock-based compensation		19,068				19,068
Repurchase of outstanding common stock				(50,665)		(50,665)
Repurchase of outstanding common stock, Shares	(2,279,526)					(2,279,526)
Treasury stock reissued		(15,264)		57,110		41,846
Treasury stock reissued, Shares	3,316,566
Tax benefit from stock based compensation		2,445				2,445
Ending balance at Jan. 29, 2012	$ 785	$ 358,327	$ 496,363	$ (225,822)	$ 535	$ 630,188
Ending balance, Shares at Jan. 29, 2012	64,964,780					64,964,780