Stockholders' Deficit - Schedule of Changes and reclassifications related to Other Comprehensive Income (Loss), net of taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period			$ 67
Losses (gains) reclassified into earnings			(122)
Other comprehensive income (loss), net of taxes	$ 187	$ 515	(55)	$ 104
Change in cumulative translation adjustment	13	0	8	0
Change in unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period	0	(2)	0	(4)
Losses (gains) reclassified into earnings	3	0	3	(5)
Other comprehensive income (loss), net of taxes	3	(2)	3	(9)
Net unrealized gains (losses) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period	162	260	75	(221)
Losses (gains) reclassified into earnings	4	247	(153)	314
Other comprehensive income (loss), net of taxes	166	507	(78)	93
Losses arising during the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period	(3)	0	(3)	0
Tax provision on amortization of actuarial loss and prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Losses (gains) reclassified into earnings	9	10	17	19
Settlements and other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Losses (gains) reclassified into earnings	1	0	0	1
Change in unrealized components of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period			(3)
Losses (gains) reclassified into earnings			17
Other comprehensive income (loss), net of taxes	7	10	14	20
Change in cumulative translation adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized losses arising during the period			(5)
Losses (gains) reclassified into earnings			11
Other comprehensive income (loss), net of taxes	$ 11	$ 0
Change in cumulative translation adjustment			$ 6	$ 0

Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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