Stockholders Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Jan. 31, 2015	Jan. 31, 2013	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Stockholders Equity [Line Items]
Preferred stock, shares authorized			5,000,000		5,000,000
Preferred stock, par value			$ 0.01		$ 0.01
Preferred stock, shares outstanding			0		0
Issuance of common stock, net of offering costs (in shares)	5,447,368	9,200,000
Underwritten public offering amount per share	$ 95.00	$ 20.13
Issuance of common stock, net of offering costs	$ 496,400	$ 173,600	$ 496,400	$ 173,572
Underwriting discounts and commissions and other estimated offering expenses	$ 21,100	$ 11,600