GUARANTY OBLIGATION AND ALLOWANCE FOR RISK-SHARING OBLIGATIONS - Schedule of Activity Related to Guaranty Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
GUARANTY OBLIGATION AND ALLOWANCE FOR RISK-SHARING OBLIGATIONS
Guaranty obligation, net of accumulated amortization - beginning balance	$ 46,870	$ 41,187
Additions, following the sale of loan	17,939	13,851
Amortization	(9,663)	(8,009)
Other	(451)	(159)
Guaranty obligation, net of accumulated amortization - ending balance	$ 54,695	$ 46,870