Investments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended							3 Months Ended																								12 Months Ended
	May 05, 2012 investments	Mar. 03, 2012	Apr. 30, 2011	Mar. 31, 2010 company	May 05, 2012 U.S. Treasury bills [Member]	Mar. 03, 2012 U.S. Treasury bills [Member]	Apr. 30, 2011 U.S. Treasury bills [Member]	May 05, 2012 Debt Securities (Auction-Rate Securities) [Member]	Mar. 03, 2012 Debt Securities (Auction-Rate Securities) [Member]	Apr. 30, 2011 Debt Securities (Auction-Rate Securities) [Member]	May 05, 2012 Student loan bonds [Member]	Mar. 03, 2012 Student loan bonds [Member]	Apr. 30, 2011 Student loan bonds [Member]	May 05, 2012 Municipal revenue bonds [Member]	Mar. 03, 2012 Municipal revenue bonds [Member]	Apr. 30, 2011 Municipal revenue bonds [Member]	May 05, 2012 Marketable Equity Securities [Member]	Mar. 03, 2012 Marketable Equity Securities [Member]	Apr. 30, 2011 Marketable Equity Securities [Member]	May 05, 2012 Common stock of Talk Talk Telecom Group PLC [Member]	Mar. 03, 2012 Common stock of Talk Talk Telecom Group PLC [Member]	Apr. 30, 2011 Common stock of Talk Talk Telecom Group PLC [Member]	May 05, 2012 Common stock of Carphone Warehouse Group plc [Member]	Mar. 03, 2012 Common stock of Carphone Warehouse Group plc [Member]	Apr. 30, 2011 Common stock of Carphone Warehouse Group plc [Member]	May 05, 2012 Marketable Equity Securities, Other [Member]	Mar. 03, 2012 Marketable Equity Securities, Other [Member]	Apr. 30, 2011 Marketable Equity Securities, Other [Member]	May 05, 2012 Other Investments [Member]	Mar. 03, 2012 Other Investments [Member]	Apr. 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	$ 20		$ 0	$ 0	$ 20
Total equity and other investments	128	140	316					66	82	97							3	3	147	0	0	87	0	0	60	3	3	0	59	55	72
Auction rate securities, interval period																																7 days	28 days	35 days
Securities redeemed	17
Investments in portfolio (investments)	14
Aggregate par value of failed auctions	71
Investments, Fair Value Disclosure								66	82	97	64	80	95	2	2	2
Auction Rate Securities, Par Value								71	88	101
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)								0.66%	0.50%	0.75%
Percentage of Portfolio With Credit Rating AAA/Aaa (as a percent)								25.00%
Percentage of Portfolio With Credit Rating AA/Aa (as a percent)								64.00%
Percentage of Portfolio With Credit Rating A/A (as a percent)								11.00%
Auction Rate Securities, Maturity Date Range, Start (in years)								4 years
Auction Rate Securities, Maturity Date Range, End (in years)								30 years
Pre-tax unrealized gain (loss) in accumulated other comprehensive income								(5)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ (3)	$ (3)	$ 71					$ (3)	$ (3)	$ (2)							$ 0	$ 0	$ 74
Number of companies formed after CPW demerger				2