Subsequent Event - Additional Information (Detail) - USD ($)	Oct. 21, 2015	Oct. 02, 2015	May. 29, 2014	Feb. 15, 2013	Feb. 09, 2012
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount			$ 35,000,000	$ 35,000,000	$ 35,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 15,265,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount	$ 35,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 50,000,000