Schedule IV - Mortgage Loans on Real Estate (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	1,001,869,994
Carrying Amount of Loans	1,001,825,294	$ 547,345,334	$ 635,260,420
Multi-family | Illinois | Senior loan in excess of 3% | Borrower A
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	0
Carrying Amount of Loans	36,781,588
Carrying Amount of Loans	$ 36,781,588
Multi-family | Illinois | Senior loan in excess of 3% | London Interbank Offered Rate (LIBOR) | Borrower A
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.30%
Multi-family | Texas | Senior loan in excess of 3% | Borrower B
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	34,690,000
Carrying Amount of Loans	34,690,000
Multi-family | Texas | Senior loan in excess of 3% | Borrower D
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	0
Carrying Amount of Loans	33,360,000
Carrying Amount of Loans	$ 33,360,000
Multi-family | Texas | Senior loan in excess of 3% | London Interbank Offered Rate (LIBOR) | Borrower B
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.05%
Multi-family | Texas | Senior loan in excess of 3% | London Interbank Offered Rate (LIBOR) | Borrower D
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.65%
Multi-family | Maryland | Senior loan in excess of 3% | Borrower C
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	33,500,000
Carrying Amount of Loans	$ 33,500,000
Multi-family | Maryland | Senior loan in excess of 3% | London Interbank Offered Rate (LIBOR) | Borrower C
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.25%
Multi-family | Virginia | Senior loan in excess of 3% | Borrower E
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	30,576,666
Carrying Amount of Loans	$ 30,576,666
Multi-family | Virginia | Senior loan in excess of 3% | London Interbank Offered Rate (LIBOR) | Borrower E
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	2.75%
Multi-family | Diversified | Senior loan less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	752,255,325
Carrying Amount of Loans	$ 752,272,465
Multi-family | Diversified | Senior loan less than 3% | Minimum | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	2.90%
Multi-family | Diversified | Senior loan less than 3% | Maximum | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	7.50%
Office | Diversified | Senior loan less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	11,748,199
Carrying Amount of Loans	$ 11,748,199
Office | Diversified | Senior loan less than 3% | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.75%
Retail | Diversified | Senior loan less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	17,172,623
Carrying Amount of Loans	$ 17,172,623
Retail | Diversified | Senior loan less than 3% | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.10%
Self-Storage | Virginia | Senior loan less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 0
Carrying Amount of Loans	51,785,593
Carrying Amount of Loans	$ 51,723,753
Self-Storage | Virginia | Senior loan less than 3% | Minimum | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	3.60%
Self-Storage | Virginia | Senior loan less than 3% | Maximum | London Interbank Offered Rate (LIBOR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Payment Rates	4.75%