Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Jul. 31, 2014
Stock-Based Compensation [Line Items]
Cash received from option exercises	$ 100,000	$ 600,000	$ 1,300,000
Stock Options
Stock-Based Compensation [Line Items]
Stock options granted, number of shares	0	179,601
Weighted average fair value of option granted		$ 11.14
Total fair value of options vested	$ 11.21	$ 15.65
Stock options, exercised	9,194	40,000
Total intrinsic value of options exercised	100,000	200,000
Nonvested Stock Options
Stock-Based Compensation [Line Items]
Stock options granted, number of shares	0
Weighted average fair value of option granted	$ 0.00
Total fair value of options vested	$ 11.21
Unrecognized compensation expense	4,700,000	7,500,000
Weighted average period	1 year 10 months 18 days	2 years 10 months 18 days
Restricted Stock
Stock-Based Compensation [Line Items]
Weighted average period	2 years 2 months 12 days	3 years
Total intrinsic value of restricted stock vested	1,000,000	600,000
Unrecognized compensation expense	4,400,000	7,300,000
Granted, Number of shares	0	95,735
Restricted Stock Units (RSUs)
Stock-Based Compensation [Line Items]
Weighted average period	3 years 2 months 18 days	3 years 6 months 18 days
Total intrinsic value of restricted stock vested	1,200,000	40,000
Unrecognized compensation expense	9,200,000	5,400,000
Granted, Number of shares	201,000
Performance shares
Stock-Based Compensation [Line Items]
Weighted average period	2 years 10 months 24 days
Total intrinsic value of restricted stock vested	0
Unrecognized compensation expense	$ 3,500,000
Performance shares, vesting percentage	40.00%
Granted, Number of shares	122,787
Performance shares issued, minimum	0.00%
Performance shares issued, maximum	200.00%
Performance shares | Share-based Compensation Award, Tranche One
Stock-Based Compensation [Line Items]
Performance shares, vesting period	3 years
Performance shares | Share-based Compensation Award, Tranche Two
Stock-Based Compensation [Line Items]
Performance shares, vesting period	2 years