Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Accumulated Other Comprehensive Income Loss [Line Items]
Balances - February 1, 2012			$ (1,410)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	969	(2,661)	848	(2,021)
Balances - October 31, 2012	(562)	(1,375)	(562)	(1,375)
Currency Translation And Other [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balances - February 1, 2012			(806)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			980
Balances - October 31, 2012	174		174
Derivative Instruments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balances - February 1, 2012			(7)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			(135)
Balances - October 31, 2012	(142)		(142)
Minimum Pension Liability [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balances - February 1, 2012			(597)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			3
Balances - October 31, 2012	$ (594)		$ (594)