Stockholders' Deficit - Schedule of Changes and Reclassifications Related to Other Comprehensive Income, Net of Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) arising during the period			$ (225)
Reclassifications of (gains) losses into earnings			328
Other comprehensive income (loss), net of taxes	$ 515	$ (45)	104	$ (276)
Change in unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized (losses) gains arising during the period	(2)	1	(4)	3
Gains reclassified into earnings	0	0	(5)	0
Unrealized gains (losses) arising during the period			(4)
Reclassifications of (gains) losses into earnings			(5)
Other comprehensive income (loss), net of taxes	(2)	1	(9)	3
Change in unrealized components of cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) arising during the period	260	(60)	(221)	(232)
Reclassifications of (gains) losses into earnings	247	(9)	314	(76)
Other comprehensive income (loss), net of taxes	507	(69)	93	(308)
Gains arising during the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) arising during the period	0	9	0	9
Tax provision on amortization of actuarial loss and prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications of (gains) losses into earnings	10	12	19	26
Curtailments, settlements and other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications of (gains) losses into earnings	0	2	1	(6)
Change in unrealized components of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) arising during the period			0
Reclassifications of (gains) losses into earnings			19
Other comprehensive income (loss), net of taxes	$ 10	$ 23	$ 20	$ 29

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

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