Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Loss Contingencies [Line Items]
Loan purchase obligation period	2 days
Contingent loan purchase commitment limit			$ 13,800
Commitment repurchases	$ 400	$ 1,900
Deposit	9,000		9,000
Loan purchase obligation	15,100	$ 21,500
Fair value	14,200		4,500
Contingent liabilities	21,291		21,592
FTC Lawsuit
Loss Contingencies [Line Items]
Contingent liabilities	$ 18,000		$ 18,000