Share-Based Compensation Plans - Stock Option Activity (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Oct. 31, 2017 USD ($) $ / shares shares
Number of Shares
Beginning balance (in shares) | shares	0.4
Forfeited or expired (in shares) | shares	0.0
Exercised (in shares) | shares	(0.1)
Ending balance (in shares) | shares	0.2
Exercisable (in shares) | shares	0.1
Weighted-Average Exercise Price per Share
Beginning balance (usd per share) | $ / shares	$ 17.74
Forfeited or expired (usd per share) | $ / shares	25.30
Exercised (usd per share) | $ / shares	20.13
Ending balance (usd per share) | $ / shares	16.29
Exercisable (usd per share) | $ / shares	$ 18.49
Weighted-Average Remaining Contractual Term (in years)
Weighted-Average Remaining Contractual Term, Outstanding (in years)	2 years	[1]
Weighted-Average Remaining Contractual Term, Exercisable (in years)	2 years	[1]
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding | $	$ 6.2	[2]
Aggregate Intrinsic Value, Exercisable | $	$ 3.2	[2]

[1] Excludes contractual terms associated with plans prior to the 2006 Equity Plan due to the uncertainty of expiration.

[2] Amount by which the current market price of our common stock on October 31, 2017 exceeds the exercise price.