Mortgages Receivable, net - CECL Allowance by CECL Allowances by loan portfolio geographical location (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023	Jan. 31, 2023
Mortgages Receivable
Total	$ 490,743,000	$ 499,235,000
Less: Allowance for credit losses	(8,053,252)	(7,523,160)	$ (7,523,160)
Carrying value, net	$ 482,690,418	$ 491,712,211
% of Portfolio	100.00%	100.00%
New England
Mortgages Receivable
Total	$ 231,026,000	$ 232,437,000
Less: Allowance for credit losses	$ (6,114,000)	$ (5,764,000)
% of Portfolio	47.10%	46.60%
Mid-Atlantic
Mortgages Receivable
Total	$ 90,678,000	$ 99,288,000
Less: Allowance for credit losses	$ (1,506,000)	$ (1,324,000)
% of Portfolio	18.50%	19.90%
South
Mortgages Receivable
Total	$ 164,938,000	$ 163,409,000
Less: Allowance for credit losses	$ (433,000)	$ (435,000)
% of Portfolio	33.60%	32.70%
West
Mortgages Receivable
Total	$ 4,101,000	$ 4,101,000
% of Portfolio	0.80%	0.80%