Notes Payable - Additional Information (Detail) - USD ($)	1 Months Ended				12 Months Ended
	May. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Aug. 31, 2014	Oct. 31, 2014	Oct. 31, 2015
Short-term Debt [Line Items]
Credit facility maximum borrowing capacity					$ 148,619,000	$ 45,102,000
Domestic Bank Debt [Member]
Short-term Debt [Line Items]
Credit facility maximum borrowing capacity					$ 100,000,000	$ 0
Domestic Bank Debt [Member] | PNC Bank [Member]
Short-term Debt [Line Items]
Domestic bank agreement days					364 days
Maximum amount borrowed under bank lines of credit				$ 100,000,000
Additional amount borrowed under bank lines of credit			$ 50,000,000
Repayments of credit facility	$ 50,000,000	$ 100,000,000
Credit facility maximum borrowing capacity			$ 150,000,000