GUARANTY OBLIGATION AND ALLOWANCE FOR RISK-SHARING OBLIGATIONS - Schedule of Activity Related to Guaranty Obligation (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
GUARANTY OBLIGATION AND ALLOWANCE FOR RISK-SHARING OBLIGATIONS
Guaranty obligation, net of accumulated amortization - beginning balance	$ 54,695	$ 46,870
Additions, following the sale of loan	1,862	4,863
Amortization	(2,267)	(2,349)
Other	1,468	(8)
Guaranty obligation, net of accumulated amortization - ending balance	$ 55,758	$ 49,376