Related Party Transactions - Summary of Balances of Transactions with Related Parties (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Cash and restricted cash deposits in affiliated bank	$ 64,724	$ 29,136
Other due/to from affiliate
Accounts receivable	39,095	25,714
Prepaid expenses and other assets	4,211	2,796
Operating lease right-of use assets	20,617	0
Other long-term assets	57	166
Accounts payable	7,250	6,344
Unearned income	35,489	25,401
Operating lease liabilities	$ 20,905	$ 0