Investments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended							6 Months Ended																								12 Months Ended
	Aug. 04, 2012	Aug. 04, 2012 investments	Mar. 03, 2012	Jul. 30, 2011	Mar. 31, 2010 company	Aug. 04, 2012 U.S. Treasury bills [Member]	Mar. 03, 2012 U.S. Treasury bills [Member]	Jul. 30, 2011 U.S. Treasury bills [Member]	Aug. 04, 2012 Debt Securities (Auction-Rate Securities) [Member]	Mar. 03, 2012 Debt Securities (Auction-Rate Securities) [Member]	Jul. 30, 2011 Debt Securities (Auction-Rate Securities) [Member]	Aug. 04, 2012 Student loan bonds [Member]	Mar. 03, 2012 Student loan bonds [Member]	Jul. 30, 2011 Student loan bonds [Member]	Aug. 04, 2012 Municipal revenue bonds [Member]	Mar. 03, 2012 Municipal revenue bonds [Member]	Jul. 30, 2011 Municipal revenue bonds [Member]	Aug. 04, 2012 Marketable Equity Securities [Member]	Mar. 03, 2012 Marketable Equity Securities [Member]	Jul. 30, 2011 Marketable Equity Securities [Member]	Aug. 04, 2012 Common stock of Talk Talk Telecom Group PLC [Member]	Mar. 03, 2012 Common stock of Talk Talk Telecom Group PLC [Member]	Jul. 30, 2011 Common stock of Talk Talk Telecom Group PLC [Member]	Aug. 04, 2012 Common stock of Carphone Warehouse Group plc [Member]	Mar. 03, 2012 Common stock of Carphone Warehouse Group plc [Member]	Jul. 30, 2011 Common stock of Carphone Warehouse Group plc [Member]	Aug. 04, 2012 Marketable Equity Securities, Other [Member]	Mar. 03, 2012 Marketable Equity Securities, Other [Member]	Jul. 30, 2011 Marketable Equity Securities, Other [Member]	Aug. 04, 2012 Other Investments [Member]	Mar. 03, 2012 Other Investments [Member]	Jul. 30, 2011 Other Investments [Member]	Mar. 03, 2012 Auction Rate Securities, Interval 1 [Member]	Mar. 03, 2012 Auction Rate Securities, Interval 2 [Member]	Mar. 03, 2012 Auction Rate Securities, Interval 3 [Member]
Schedule of Investments
Total short-term investments	$ 0	$ 0	$ 0	$ 80		$ 0	$ 0	$ 80
Total equity and other investments	91	91	140	316					22	82	91							3	3	150	0	0	88	0	0	61	3	3	1	66	55	75
Auction rate securities, interval period																																	7 days	28 days	35 days
Securities redeemed	47
Investments in portfolio (investments)		7
Aggregate par value of failed auctions	24	24
Investments, Fair Value Disclosure									22			20	80	89	2	2	2
Auction Rate Securities, Par Value									24	88	93
Guaranteed or Insured Percentage, Low Range (as a percent)												95.00%
Guaranteed or Insured Percentage, High Range (as a percent)												100.00%
Percentage Insured by Rated Bond Insurers (as a percent)															100.00%
Weighted Average Interest Rate Percentage (as a percent)									0.69%	0.50%	0.32%
Percentage of Portfolio With Credit Rating AAA/Aaa (as a percent)									39.00%
Percentage of Portfolio With Credit Rating AA/Aa (as a percent)									29.00%
Percentage of Portfolio With Credit Rating A/A (as a percent)									32.00%
Auction Rate Securities, Maturity Date Range, Start (in years)									4 years
Auction Rate Securities, Maturity Date Range, End (in years)									29 years
Pre-tax unrealized gain (loss) in accumulated other comprehensive income									(2)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ (1)	$ (1)	$ (3)	$ 76					$ (1)	$ (3)	$ (1)							$ 1	$ 0	$ 77
Number of companies formed after CPW demerger					2