Assets Held for Sale (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2016	Mar. 01, 2016	Jan. 31, 2016	Apr. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held for Sale, Assets, Current			$ 48	$ 0
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held for Sale, Inventory, Current			10
Assets Held for Sale, Goodwill, Current			16
Assets Held for Sale, Intangible Assets, Current			22
Assets Held for Sale, Assets, Current			$ 48
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 483
Subsequent Event [Member] | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Consideration		$ 542