Equity - Schedule of Basic and Diluted Earnings Per Share, or EPS, Based on Weighted-Average of Both Restricted and Unrestricted Class A Common Stock Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income	$ 64,794	$ 66,888	$ 184,921	$ 131,564
Weighted-average shares outstanding, basic and diluted	94,071,537	93,357,960	94,067,923	77,752,247
Per share amount, basic and diluted	$ 0.69	$ 0.72	$ 1.97	$ 1.69