STOCKHOLDERS' EQUITY - Stock Repurchase Program (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Nov. 19, 2018
Share repurchase program
Shares repurchased in the period (Value)	$ 126	$ 50	$ 186	$ 125
Shares retired (Cost method)	$ 0	$ 0	$ 0	$ 0
2019 Repurchase Program [Member]
Share repurchase program
Share repurchase program authorized amount					$ 1,750
Shares repurchased and retired during period, (Shares)	1,663,000		2,389,000
Shares repurchased and retired during period, (Value)	$ 126		$ 186
Shares repurchased in the period (in shares)		638,000		1,766,000
Shares repurchased in the period (Value)		$ 50		$ 125
Shares retired (in shares)		629,000		1,757,000
Shares retired (Cost method)		$ 49		$ 124
Remaining authorized repurchase amount under share repurchase program	$ 841		$ 841