COMMITMENTS AND CONTINGENCIES (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) transaction	Jun. 30, 2020 USD ($) transaction	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	$ (67,563,000)	$ 94,754,000	$ (87,723,000)	$ 151,400,000
Allowance for credit losses	132,418,000	232,192,000	132,418,000	232,192,000	$ 204,818,000	$ 228,804,000	$ 139,073,000	$ 47,576,000
(Recovery of) provision for credit losses	(67,563,000)	94,754,000	(87,723,000)	151,400,000
Unfunded Lending Commitment
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	(800,000)	3,400,000	(200,000)	3,300,000
Allowance for credit losses	8,100,000		8,100,000			$ 8,200,000
(Recovery of) provision for credit losses	$ (800,000)	$ 3,400,000	(200,000)	$ 3,300,000
Secondary Market Loan Sales
Guarantor Obligations [Line Items]
Provision for losses at the time of sale			$ 0
Number of loans repurchased | transaction			0	0
(Recovery of) provision for credit losses			$ 0