Stockholders' Equity - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Jan. 22, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Number of votes per share	one vote per share
Common stock, shares authorized	500,000,000		500,000,000
Common stock, shares issued	85,490,296		84,979,869
Common stock, shares outstanding	85,490,296		84,979,869
Treasury stock, shares	0		0
Common stock repurchased and retired	$ 14,774,000
Series A Convertible Preferred Stock, shares authorized	25,000,000		25,000,000
Series A Convertible Preferred Stock, shares issued	0		0
Series A Convertible Preferred Stock, shares outstanding	0		0
Common stock
Class Of Stock [Line Items]
Stock repurchase program, announced date	Jan. 25, 2016
Common stock repurchased and retired, Shares	724,473
Common stock repurchased and retired, Average Price Paid per Share	$ 20.37
Common stock repurchased and retired	$ 14,774,000
Maximum | Common stock
Class Of Stock [Line Items]
Authorized to repurchase of common stock		$ 100,000,000