Stockholders' Equity - Changes and Reclassifications Of OCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	$ 75	$ 114	$ 145	$ 38
Net unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive (loss) income before reclassifications	(8)	3	(6)	5
(Gains) losses reclassified into earnings	(4)	0	(7)	(3)
Other comprehensive income, net of taxes	(12)	3	(13)	2
Change in net unrealized gains (losses) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive (loss) income before reclassifications	274	111	339	144
(Gains) losses reclassified into earnings	(202)	(60)	(262)	(177)
Other comprehensive income, net of taxes	72	51	77	(33)
Change in unrealized components of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive (loss) income before reclassifications			9
(Gains) losses reclassified into earnings			115
Other comprehensive income, net of taxes	55	62	124	62
Net unrealized (losses) gains arising during the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Gains) losses reclassified into earnings	(8)	6	9	(39)
Amortization of actuarial loss and prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Gains) losses reclassified into earnings	57	52	114	101
Curtailments, settlements and other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	6	4	1	0
Change in cumulative translation adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive (loss) income before reclassifications			(43)
(Gains) losses reclassified into earnings			0
Other comprehensive income, net of taxes	$ (40)	$ (2)	$ (43)	$ 7