Fair Values of Financial Instruments (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Line of Credit	$ 0	$ 22,000,000
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real Estate Loans	213,458,000	302,423,000
Note Receivable And Line Of Credit Receivable	9,011,000	10,874,000
Assets, Fair Value Disclosure	222,469,000	313,297,000
Mortgage Loan Payable	2,382,652,000	2,640,705,000
Long-term Line of Credit	0	22,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	2,382,652,000	2,662,705,000
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real Estate Loans	219,923,000	315,074,000
Note Receivable And Line Of Credit Receivable	9,011,000	10,874,000
Assets, Fair Value Disclosure	228,934,000	325,948,000
Mortgage Loan Payable	2,414,774,000	2,666,471,000
Long-term Line of Credit	0	22,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	2,414,774,000	2,688,471,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real Estate Loans	0	0
Note Receivable And Line Of Credit Receivable	0	0
Assets, Fair Value Disclosure	0	0
Mortgage Loan Payable	0	0
Long-term Line of Credit	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real Estate Loans	0	0
Note Receivable And Line Of Credit Receivable	0	0
Assets, Fair Value Disclosure	0	0
Mortgage Loan Payable	0	0
Long-term Line of Credit	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real Estate Loans	219,923,000	315,074,000
Note Receivable And Line Of Credit Receivable	9,011,000	10,874,000
Assets, Fair Value Disclosure	228,934,000	325,948,000
Mortgage Loan Payable	2,414,774,000	2,666,471,000
Long-term Line of Credit	0	22,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 2,414,774,000	$ 2,688,471,000