Net Income Per Common Share - Calculations of Basic and Diluted Net Income Per Common Share (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 19.4	$ 16.0	$ 47.7	$ 48.7
Weighted-average common and common equivalent shares outstanding-Basic (in shares)	56.2	55.0	56.0	54.7
Effect of dilutive securities:
Weighted-average common and common equivalent shares outstanding-Diluted (in shares)	57.0	56.3	57.0	55.9
Net income per common share - basic (in usd per share)	$ 0.34	$ 0.29	$ 0.85	$ 0.89
Net income per common share - diluted (in usd per share)	$ 0.34	$ 0.29	$ 0.84	$ 0.87
RSUs (in shares)
Effect of dilutive securities:
Effect of dilutive securities	0.4	0.5	0.4	0.5
Stock options (in shares)
Effect of dilutive securities:
Effect of dilutive securities	0.3	0.4	0.4	0.3
Performance shares (in shares)
Effect of dilutive securities:
Effect of dilutive securities	0.1	0.4	0.2	0.4