Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Investments (Details) (USD $)	6 Months Ended
Investments (Details) (USD $)	Aug. 02, 2014	Aug. 03, 2013	Feb. 01, 2014
Available-for-sale securities
Amortized Cost	$ 15,845,000
Unrealized Gains	6,000
Unrealized Losses	15,000
Estimated Fair Value	15,836,000
Total investments			16,100,000
Purchases of available-for-sale securities	6,497,000	10,816,000
Maturities and sales of available-for-sale securities	6,740,000	950,000
Other than temporary impairment of available-for-sale securities	0	0
Expected maturities of available-for-sale securities
Due in one year or less	12,434,000
Due after one year through five years	3,402,000
Short-term investments
Available-for-sale securities
Amortized Cost	12,442,000
Unrealized Gains	3,000
Unrealized Losses	11,000
Estimated Fair Value	12,434,000
Long-term investments
Available-for-sale securities
Amortized Cost	3,403,000
Unrealized Gains	3,000
Unrealized Losses	4,000
Estimated Fair Value	3,402,000
Certificates of deposit \| Short-term investments
Available-for-sale securities
Amortized Cost	5,920,000
Unrealized Gains	0
Unrealized Losses	10,000
Estimated Fair Value	5,910,000
Commercial paper \| Short-term investments
Available-for-sale securities
Amortized Cost	3,697,000
Unrealized Gains	0
Unrealized Losses	1,000
Estimated Fair Value	3,696,000
Corporate bonds \| Short-term investments
Available-for-sale securities
Amortized Cost	2,024,000
Unrealized Gains	3,000
Unrealized Losses	0
Estimated Fair Value	2,027,000
Corporate bonds \| Long-term investments
Available-for-sale securities
Amortized Cost	2,285,000
Unrealized Gains	1,000
Unrealized Losses	4,000
Estimated Fair Value	2,282,000
U.S. Agency securities \| Short-term investments
Available-for-sale securities
Amortized Cost	801,000
Unrealized Gains	0
Unrealized Losses	0
Estimated Fair Value	801,000
U.S. Agency securities \| Long-term investments
Available-for-sale securities
Amortized Cost	900,000
Unrealized Gains	0
Unrealized Losses	0
Estimated Fair Value	900,000
Municipal bonds \| Long-term investments
Available-for-sale securities
Amortized Cost	218,000
Unrealized Gains	2,000
Unrealized Losses	0
Estimated Fair Value	$ 220,000