Mortgage Loans, Construction Loan and Interest Rate Swaps (Details) $ in Thousands		3 Months Ended		12 Months Ended
	Apr. 21, 2022 USD ($) item	Mar. 31, 2022 USD ($) item	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Long-Term Debt
Mortgage loans, net of debt issuance costs		$ 168,950		$ 169,818
Debt disclosures
Payment on secured debt		$ 1,076	$ 1,267
Interest rate swap agreement
Debt disclosures
Number of agreements containing credit risk related contingent features | item		0
Recognized net gains (losses) (included in other comprehensive loss), before taxes, on interest rate swap agreements		$ 4,662	3,479
Loss expected to be reclassified over next twelve months from accumulated other comprehensive loss to interest expense		(361)
Interest expense		$ 451	$ 488
LIBOR | Maximum
Debt disclosures
Variable interest rate margin (as a percent)		1.40%		1.40%
Nonrecourse mortgage loans
Long-Term Debt
Loans, prior to debt issuance costs		$ 144,592		$ 145,668
Debt issuance costs, net		(1,677)		(1,745)
Mortgage loans, net of debt issuance costs		$ 142,915		$ 143,923
Weighted average interest rate		3.76%		3.76%
Construction loan
Long-Term Debt
Loans, prior to debt issuance costs		$ 26,342		$ 26,273
Debt issuance costs, net		(307)		(378)
Mortgage loans, net of debt issuance costs		26,035		25,895
Delayed Draw Term Loan Facility
Long-Term Debt
Interest rate (as a percent)	1.15%
Debt disclosures
Maximum borrowing capacity	$ 150,000
Term of debt	5 years
Interest rate	4.15%
Number of separate draws | item	3
Number of facilities with minimum draw amount | item	2
Minimum draw amount	$ 25,000
Existing Credit Facility
Debt disclosures
Maximum borrowing capacity	100,000
New Credit Facility
Debt disclosures
Maximum borrowing capacity	$ 250,000
New Credit Facility | LIBOR
Debt disclosures
Variable interest rate margin (as a percent)	1.20%
4.39%, due January 2, 2025
Long-Term Debt
Loans, prior to debt issuance costs		$ 17,661		$ 17,824
Interest rate (as a percent)		4.39%		4.39%
4.17%, due May 1, 2026
Long-Term Debt
Loans, prior to debt issuance costs		$ 12,185		$ 12,291
Interest rate (as a percent)		4.17%		4.17%
3.79%, November 17, 2026
Long-Term Debt
Loans, prior to debt issuance costs		$ 22,958		$ 23,152
Interest rate (as a percent)		3.79%		3.79%
4.39%, due August 1, 2027
Long-Term Debt
Loans, prior to debt issuance costs		$ 9,405		$ 9,476
Interest rate (as a percent)		4.39%		4.39%
3.97%, due September 1, 2027
Long-Term Debt
Loans, prior to debt issuance costs		$ 11,111		$ 11,174
Interest rate (as a percent)		3.97%		3.97%
4.57%, due February 1, 2028
Long-Term Debt
Loans, prior to debt issuance costs		$ 17,025		$ 17,145
Interest rate (as a percent)		4.57%		4.57%
3.60%, due January 2, 2030
Long-Term Debt
Loans, prior to debt issuance costs		$ 6,139		$ 6,182
Interest rate (as a percent)		3.60%		3.60%
3.48% due February 1 2030
Long-Term Debt
Loans, prior to debt issuance costs		$ 14,186		$ 14,287
Interest rate (as a percent)		3.48%		3.48%
3.50%, due July 1, 2030
Long-Term Debt
Loans, prior to debt issuance costs		$ 4,881		$ 4,914
Interest rate (as a percent)		3.50%
4.33%, due August 1, 2030
Long-Term Debt
Loans, prior to debt issuance costs		$ 15,770		$ 15,867
Interest rate (as a percent)		4.33%		4.33%
4.51%, due April 1, 2034
Long-Term Debt
Loans, prior to debt issuance costs		$ 13,271		$ 13,356
Interest rate (as a percent)		4.51%		4.51%