Investments (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended				9 Months Ended				12 Months Ended
	Mar. 31, 2010 company	Nov. 26, 2011		Nov. 27, 2010		Nov. 26, 2011 investments		Nov. 27, 2010		Mar. 01, 2008	Feb. 26, 2011
Schedule of Investments
Total short-term investments		$ 0		$ 2		$ 0		$ 2			$ 22
Total equity and other investments		146		343		146		343			328
Interval of auction process		seven, 28 and 35 days
Securities redeemed		4
Investments in portfolio (investments)						18
Aggregate par value of failed auctions		89				89
Marketable Equity Security, Ownership Percentage as of Purchase Date (as a percent)										3.00%
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax		(5)		69		(5)		69			72
Number of companies formed after CPW demerger	2
Percentage ownership of former CPW in Best Buy Europe, included in Carphone Warehouse holding company (as a percent)	50.00%
Gain on sale of investments		55		0		55		0
Money Market Fund
Schedule of Investments
Total short-term investments		0		2		0		2			2
U.S. Treasury bills
Schedule of Investments
Total short-term investments		0		0		0		0			20
Debt Securities (Auction-Rate Securities)
Schedule of Investments
Total equity and other investments		81		131		81		131			110
Investments, Fair Value Disclosure		81	[1]	131	[1]	81	[1]	131	[1]		110	[1]
Auction Rate Securities, Par Value		89		141		89		141			115
Weighted Average Interest Rate Percentage (as a percent)		0.46%		0.91%		0.46%		0.91%			0.80%
Percentage of Portfolio With Credit Rating AAA/Aaa (as a percent)		88.00%				88.00%
Percentage of Portfolio With Credit Rating AA/Aa (as a percent)		3.00%				3.00%
Percentage of Portfolio With Credit Rating A/A (as a percent)		9.00%				9.00%
Auction Rate Securities, Maturity Date Range, Start (in years)						5 years
Auction Rate Securities, Maturity Date Range, End (in years)						30 years
Pre-tax unrealized gain (loss) in accumulated other comprehensive income						(8)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax		(5)		(6)		(5)		(6)			(3)
Student loan bonds
Schedule of Investments
Investments, Fair Value Disclosure		79		113		79		113			108
Guaranteed or Insured Percentage, Low Range (as a percent)		95.00%				95.00%
Guaranteed or Insured Percentage, High Range (as a percent)		100.00%				100.00%
Municipal revenue bonds
Schedule of Investments
Investments, Fair Value Disclosure		2		18		2		18			2
Percentage Insured by Rated Bond Insurers (as a percent)		100.00%				100.00%
Marketable Equity Securities
Schedule of Investments
Total equity and other investments		1		145		1		145			146
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax		0		75		0		75			75
Proceeds from Sale of Available-for-sale Securities, Equity		112
Gain on sale of investments		55
Common stock of Talk Talk Telecom Group PLC
Schedule of Investments
Total equity and other investments		0		63		0		63			62
Proceeds from Sale of Available-for-sale Securities, Equity		51
Common stock of Carphone Warehouse Group plc
Schedule of Investments
Total equity and other investments		0		78		0		78			84
Proceeds from Sale of Available-for-sale Securities, Equity		61
Marketable Equity Securities, Other
Schedule of Investments
Total equity and other investments		1		4		1		4			0
Other Investments
Schedule of Investments
Total equity and other investments		$ 64		$ 67		$ 64		$ 67			$ 72

[1] The par value and weighted-average interest rates (taxable equivalent) of our ARS were $89, $115 and $141, and 0.46%, 0.80% and 0.91%, respectively, at November 26, 2011, February 26, 2011, and November 27, 2010, respectively.