Commitments, Contingencies and Credit Risk - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) Investor State	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) Investor State	Sep. 30, 2019 USD ($)
Loss Contingencies [Line Items]
Repurchase or indemnification requests for loans sold | $	$ 0		$ 0
Lease expiration year	2034
Rental expenses under operating leases | $	$ 460	$ 372	$ 969	$ 1,101
Mortgage World Bankers Inc
Loss Contingencies [Line Items]
Total loan volume insured	7.60%		7.60%
Total loan volume sold	62.20%		62.20%
Number of investors loan volume sold | Investor	3		3
Number of states in which loan closed | State	5		5
Total closed loan volume	98.00%		98.00%
Number of states in which loan closed | State	2		2