Goodwill and Intangible Assets - Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016	Oct. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 6,340		$ 6,340		$ 5,762
Fully amortized intangibles	89		89
Amortization of intangible assets	132	$ 111	340	$ 331
In-process research and development
Finite-Lived Intangible Assets [Line Items]
Transfers			1
SGI
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	582		582
SGI | In-process research and development
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 85		$ 85