CURRENT EXPECTED CREDIT LOSSES - Internal Credit Risk Rating (Details) - Loans Held for Investment $ in Thousands	Dec. 31, 2020 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 429,785
2019	613,244
2018	428,847
2017	292,722
2016	16,492
Prior	34,129
Total	1,815,219
1 - Very Low Risk
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	8,547
2017	0
2016	0
Prior	0
Total	8,547
2 - Low Risk
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	109,429
2018	66,055
2017	68,438
2016	0
Prior	0
Total	243,922
3 - Medium risk
Financing Receivable, Credit Quality Indicator [Line Items]
2020	429,785
2019	468,721
2018	254,858
2017	201,627
2016	16,492
Prior	0
Total	1,371,483
4 - Higher Risk: Asset Performance is trailing underwritten expectations. Loan at risk of impairment without mater improvement to performance
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	35,094
2018	99,387
2017	22,657
2016	0
Prior	34,129
Total	191,267
5 - Impaired/Loss Possible: A loan that has a significantly increased probability of default or principal loss
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Total	$ 0