Net Income Per Common Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0.1	0.2	0.2	0.2