Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Transaction fee refund reserve		$ 18,798	$ 25,541
Contingent liabilities		16,375	16,000
Accrued expenses		15,709	36,797
Accrued compensation		10,334	30,484
Loan trailing fee liability, at fair value		9,213	11,099
Deferred revenue		4,801	13,688
Other		11,139	9,027
Total accrued expenses and other liabilities	[1]	$ 86,369	$ 142,636

[1] Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.