Stockholders' Equity and Earnings Per Share ("EPS") - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders Equity Note [Line Items]
Proceeds from issuance of common stock	$ 434,900	$ 0	$ 434,866	$ 0
Common stock
Stockholders Equity Note [Line Items]
Common stock issued in public offering (in shares)	4,485,000		4,485,000
Common stock offering price per share (usd per share)	$ 101.00