Accumulated Other Comprehensive Income (Loss) (Details) $ in Millions	6 Months Ended
	Jul. 31, 2015 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances - Beginning of Period	$ (7,168)
Other Comprehensive Income (Loss) Before Reclassifications	(1,234)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	14
Balances - End of Period	(8,388)
Currency Translation And Other [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances - Beginning of Period	(7,011)
Other Comprehensive Income (Loss) Before Reclassifications	(1,194)
Balances - End of Period	(8,205)
Net Investment Hedges [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances - Beginning of Period	656
Other Comprehensive Income (Loss) Before Reclassifications	(81)
Balances - End of Period	575
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances - Beginning of Period	(134)
Other Comprehensive Income (Loss) Before Reclassifications	(39)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	20
Balances - End of Period	(153)
Minimum Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances - Beginning of Period	(679)
Other Comprehensive Income (Loss) Before Reclassifications	80
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(6)
Balances - End of Period	$ (605)