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Basis of Presentation - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Nov. 01, 2018	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2018	Oct. 31, 2018
Retained Earnings Adjustments [Line Items]
Accumulated deficit	$ 1,036	$ 1,068			$ 473
ASU 2018-02 \| Early adoption
Retained Earnings Adjustments [Line Items]
Reclassification from accumulated other comprehensive income to accumulated deficit		$ 69
ASU 2017-07 \| Selling, general and administrative expenses
Retained Earnings Adjustments [Line Items]
Reduction in interest and other			$ 62	$ 180
ASU 2017-07 \| Interest and other
Retained Earnings Adjustments [Line Items]
Reduction in interest and other			$ 62	$ 180
ASU 2016-16
Retained Earnings Adjustments [Line Items]
Prepaid Taxes	353
Accumulated deficit	353
Adjustments under Topic 606
Retained Earnings Adjustments [Line Items]
Decrease in retained earnings	$ (212)