Taxes on Earnings - Deferred Tax Asset Valuation Allowance (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	$ 8,807	$ 8,520	$ 7,114	$ 8,231
Increase (decrease) in valuation allowances	300	1,400	(1,100)
Deferred tax asset valuation allowance
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	$ 8,800	$ 8,500	$ 7,100