This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Company may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months.

+ References+ Details

Fair Value Measurements (Financial Assets Valued On A Recurring Or Non-Recurring Basis, Based On The Priority Of The Inputs To The Valuation Technique) (USD $) In Thousands	Jul. 30, 2011	Jan. 29, 2011	Jul. 31, 2010
Deferred compensation plan	$ 4,256	$ 4,143	$ 3,815
Total	462,362	543,559	475,111
Corporate Bond [Member]
Marketable securities	162,914	2,055	12,453
Corporate Bond [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Corporate Bond [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	162,914	2,055	12,453
Corporate Bond [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Asset-Backed Securities [Member]
Marketable securities	616	3,031	8,961
Asset-Backed Securities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Asset-Backed Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	616	3,031	8,961
Asset-Backed Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Variable Rate Demand Notes [Member]
Marketable securities		319,220	230,728
Variable Rate Demand Notes [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Variable Rate Demand Notes [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities		319,220	230,728
Variable Rate Demand Notes [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Certificates Of Deposit [Member]
Marketable securities	2,072
Certificates Of Deposit [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Certificates Of Deposit [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	2,072
Certificates Of Deposit [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Commercial Paper [Member]
Marketable securities	45,064
Commercial Paper [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Commercial Paper [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	45,064
Commercial Paper [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Money Market Accounts [Member]
Cash equivalents	9,895	5,397	1,467
Money Market Accounts [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Cash equivalents	9,895	5,397	1,467
Money Market Accounts [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Cash equivalents
Money Market Accounts [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Cash equivalents
U.S. Government Securities [Member]
Marketable securities	100,719	58,554	59,130
U.S. Government Securities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities	52,890	58,554	59,130
U.S. Government Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	47,829
U.S. Government Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Municipal Securities [Member]
Marketable securities	136,826	151,159	158,557
Municipal Securities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Marketable securities
Municipal Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Marketable securities	136,826	151,159	158,557
Municipal Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Deferred compensation plan	4,256	4,143	3,815
Total	67,041	68,094	64,412
Significant Other Observable Inputs (Level 2) [Member]
Deferred compensation plan
Total	395,321	475,465	410,699
Significant Unobservable Inputs (Level 3) [Member]
Deferred compensation plan
Total