Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Mortgage Receivable and Notes Receivable (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2019	Mar. 31, 2022	Dec. 31, 2021
MORTGAGE RECEIVABLE AND NOTES RECEIVABLE
Mortgage loans receivable at fair value		$ 0	$ 43,276
Multi Family Same-Store \| Ironwood Apartments - New Hope, MN \| Tax Increment Financing
MORTGAGE RECEIVABLE AND NOTES RECEIVABLE
Loan commitment		$ 6,100	6,400
Multi-Family Residential \| Ironwood Apartments - New Hope, MN \| Tax Increment Financing
MORTGAGE RECEIVABLE AND NOTES RECEIVABLE
Interest rate		4.50%
Multi-Family Residential \| Minneapolis, Minnesota \| Construction Loans
MORTGAGE RECEIVABLE AND NOTES RECEIVABLE
Interest rate	4.50%
Mortgage loans receivable at fair value	$ 29,900		29,900
Multi-Family Residential \| Minneapolis, Minnesota \| Mezzanine Loan
MORTGAGE RECEIVABLE AND NOTES RECEIVABLE
Interest rate	11.50%
Mortgage loans receivable at fair value	$ 15,300		$ 13,400