Other Expenses - Schedule of General and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Professional services	$ 1,662	$ 1,096
Operating and other costs	1,451	449
Subtotal	3,113	1,545
Non-cash compensation expenses
Restricted class A common stock earned	8,553	7,643
Director stock-based compensation	125	125
Subtotal	8,678	7,768
Total general and administrative expenses	$ 11,791	$ 9,313