Share-Based Compensation Plans - Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of granted purchase rights per share (usd per share)	$ 1.77	$ 1.70	$ 2.11
Common stock issued (in shares)	0.1	0.1	0.1
Fair value of common stock issued per share (usd per share)	$ 33.60	$ 32.34	$ 40.07
Aggregate purchases	$ 4.1	$ 4.7	$ 4.7