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
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 57,047	$ 35,393
Weighted-average shares outstanding, basic and diluted	94,067,769	58,576,025
Per share amount, basic and diluted	$ 0.61	$ 0.60