Fair Value (Summary Of Financial Assets Measured At Fair Value On Recurring Basis) (Details) (USD $) In Thousands	Jul. 31, 2011	Jan. 30, 2011
Financial Assets	$ 173,019	$ 139,323
Agency Securities [Member]
Financial Assets	53,363	54,747
Agency Securities [Member] | Quoted Prices In Active Markets For Identical (Level 1) [Member]
Financial Assets
Agency Securities [Member] | Observable Inputs Other Than Level 1 (Level 2) [Member]
Financial Assets	53,363	54,747
Corporate Issues [Member]
Financial Assets	13,656	16,576
Corporate Issues [Member] | Quoted Prices In Active Markets For Identical (Level 1) [Member]
Financial Assets
Corporate Issues [Member] | Observable Inputs Other Than Level 1 (Level 2) [Member]
Financial Assets	13,656	16,576
Bank Time Deposits [Member]
Financial Assets	106,000	68,000
Bank Time Deposits [Member] | Quoted Prices In Active Markets For Identical (Level 1) [Member]
Financial Assets
Bank Time Deposits [Member] | Observable Inputs Other Than Level 1 (Level 2) [Member]
Financial Assets	106,000	68,000
Quoted Prices In Active Markets For Identical (Level 1) [Member]
Financial Assets
Observable Inputs Other Than Level 1 (Level 2) [Member]
Financial Assets	$ 173,019	$ 139,323