ALLOWANCE FOR RISK-SHARING OBLIGATIONS AND GUARANTY OBLIGATION - Summary of Allowance for Risk-Sharing Obligations (Detail) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) loan	Sep. 30, 2021 USD ($)	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Allowance for Risk-Sharing Contracts
Beginning balance	$ 48,475	$ 62,636	$ 61,607	$ 60,329	$ 62,636	$ 75,313
Provision (benefit) for risk-sharing obligations	1,183			1,278	(12,978)	(13,706)
Ending balance	49,658		62,636	61,607	$ 49,658	61,607
Number of defaulted loans | loan					3
Amount of specific reserves placed on defaulted at risk loans	10,800		$ 10,300		$ 10,800
Fannie Mae DUS program
Allowance for Risk-Sharing Contracts
Maximum quantifiable contingent liability associated with guarantees	$ 10,800,000			$ 9,800,000	$ 10,800,000	$ 9,800,000
Fannie Mae DUS Program
Allowance for Risk-Sharing Contracts
Period of time used to determine the historical loss rate		10 years
Charge off rate for forecasted period		0.03%					0.022%	0.03%	0.04%	0.06%
Charge off rate for the remaining period	0.012%		0.018%		0.012%
At risk servicing portfolio	$ 52,100,000				$ 52,100,000
CECL reserve for at risk servicing portfolio	$ 38,900		$ 52,300		$ 38,900
Weighted average remaining life of the at risk servicing portfolio			7 years 6 months		7 years 3 months 18 days