Preferred and Common Stock - Repurchase Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Stockholders' Equity Note [Abstract]
Total number of shares repurchased (in shares)	0.2	1.4	1.0
Average price paid per share (usd per share)	$ 40.07	$ 33.48	$ 30.72
Total cash paid for share repurchase	$ 7.9	$ 46.6	$ 31.4