Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Apr. 30, 2020		Apr. 30, 2019		Apr. 30, 2020		Apr. 30, 2019		Oct. 31, 2018
Cash dividends declared (in dollars per share)		$ 0.12		$ 0.1125		$ 0.24		$ 0.225
Stockholders' equity		$ 16,258				$ 16,258
Cumulative Effect, Period of Adoption, Adjustment
Stockholders' equity	[1]	0				0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2014-09
Stockholders' equity				$ 143				$ 143
Accumulated Deficit
Stockholders' equity		(8,385)		(7,765)		(8,385)		(7,765)		$ (5,899)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment
Stockholders' equity		$ 43	[1]	$ (2,162)	[2]	$ 43	[1]	$ (2,162)	[2]
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-16
Stockholders' equity										$ 2,300

[1] Represents the impact of the adoption of an accounting standard update that allows for the reclassification of stranded tax effects from accumulated other comprehensive loss to accumulated deficit.

[2] $2.3 billion was related to a reduction to retained earnings as a result of the adoption of an accounting standard update for Income Taxes and $143 million was related to an addition to retained earnings as a result of the adoption of the new revenue accounting standard.