SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Provision (Benefit) for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of Provision (Benefit) for Credit Losses
Provision (benefit) for loan losses	$ 58	$ 4	$ 706	$ 69
Provision (benefit) for risk-sharing obligations	(830)	515	2,158	773
Provision (benefit) for credit losses	$ (772)	$ 519	$ 2,864	$ 842