SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Provision (Benefit) for Credit Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of Provision (Benefit) for Credit Losses
Provision (benefit) for loan losses	$ 875	$ 128	$ (294)
Provision (benefit) for risk-sharing obligations	6,398	680	51
Provision (benefit) for credit losses	$ 7,273	$ 808	$ (243)