Stockholders' Equity - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013
Equity [Abstract]
Dividend paid	$ 0	$ 17,900,000
Approved amount for open market repurchase of common stock			$ 100,000,000
Stock Purchased Under Open Market Amount	$ 0	$ 0