Subsequent Events - Additional Information (Detail) - Subsequent Event	Oct. 15, 2015 USD ($)
Subsequent Event [Line Items]
Increase of expenditure limit for the Company's Stock Repurchase Program	$ 50,000,000
Before Increase
Subsequent Event [Line Items]
Stock Repurchase Program limit	475,000,000
After Increase
Subsequent Event [Line Items]
Stock Repurchase Program limit	$ 525,000,000