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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 74,897	$ 78,165	$ 226,635	$ 211,436
Weighted-average shares outstanding, basic and diluted	134,536,683	116,203,140	128,485,701	111,251,864
Per share amount, basic and diluted	$ 0.56	$ 0.67	$ 1.76	$ 1.90