COMMITMENTS AND CONTINGENCIES (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) transaction	Sep. 30, 2019 USD ($) transaction	Jun. 30, 2020 USD ($)	Jan. 01, 2020 USD ($)	Dec. 31, 2019 USD ($)
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	$ 2,716,000	$ 4,121,000	$ 154,116,000	$ 23,970,000
Allowance for credit losses	232,726,000	47,671,000	232,726,000	47,671,000	$ 232,192,000		$ 47,576,000
Provision for credit losses	2,716,000	4,121,000	154,116,000	23,970,000
Provision	450,000		5,090,000
Impact of ASC 326 Adoption
Guarantor Obligations [Line Items]
Allowance for credit losses							35,855,000
Unfunded Lending Commitment
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	900,000		4,100,000
Allowance for credit losses	8,600,000		8,600,000				$ 1,500,000
Provision for credit losses	$ 900,000		4,100,000
Provision		$ 200,000		$ 700,000
Unfunded Lending Commitment | Impact of ASC 326 Adoption
Guarantor Obligations [Line Items]
Allowance for credit losses						$ 3,000,000.0
Secondary Market Loan Sales
Guarantor Obligations [Line Items]
Provision for losses at the time of sale			$ 0
Number of loans repurchased | transaction			0	1
Loans repurchased				$ 200,000
Provision for credit losses			$ 0