Contingencies Schedule of FCPA Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Foreign Corrupt Practices Act Expenses [Line Items]
Foreign corrupt practices act related expenses	$ 30	$ 41	$ 93	$ 137
Compliance programs and organizational enhancements
Foreign Corrupt Practices Act Expenses [Line Items]
Foreign corrupt practices act related expenses	8	11	23	42
Inquiry and investigation expense
Foreign Corrupt Practices Act Expenses [Line Items]
Foreign corrupt practices act related expenses	$ 22	$ 30	$ 70	$ 95