Net Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Numerator:
Earnings from continuing operations	$ 480	$ (27)	$ 419	$ 177	$ (772)	$ 452	$ 850	$ 1,482	$ 1,049	$ 2,012	$ 436
Net loss from discontinued operations									0	(104)	(92)
Net earnings									$ 1,049	$ 1,908	$ 344
Denominator:
Weighted-average shares used to compute basic net EPS (in shares)									1,353	1,529	1,646
Dilutive effect of employee stock plans (in shares)									13	24	28
Weighted-average shares used to compute diluted net EPS (in shares)									1,366	1,553	1,674
Basic net earnings (loss) per share:
Continuing operations (in dollars per share)					$ (0.53)	$ 0.30	$ 0.55	$ 0.93	$ 0.78	$ 1.32	$ 0.26
Discontinued operations (in dollars per share)									0	(0.07)	(0.05)
Total basic net earnings per share (in dollars per share)	$ 0.37	$ (0.02)	$ 0.31	$ 0.13					0.78	1.25	0.21
Diluted net earnings (loss) per share:
Continuing operations (in dollars per share)					$ (0.53)	$ 0.29	$ 0.54	$ 0.92	0.77	1.30	0.26
Discontinued operations (in dollars per share)									0	(0.07)	(0.05)
Total diluted net earnings per share (in dollars per share)	$ 0.36	$ (0.02)	$ 0.30	$ 0.13					$ 0.77	$ 1.23	$ 0.21
Anti-dilutive weighted average stock awards (in shares)									4	2	8