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, 2017	Oct. 31, 2016	Oct. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of granted purchase rights per share (usd per share)	$ 2.11	$ 1.63	$ 1.51
Common stock issued	0.1	0.2	0.2
Fair value of common stock issued per share (usd per share)	$ 40.07	$ 30.94	$ 28.77
Aggregate purchases	$ 4.7	$ 4.7	$ 4.7