Mortgage and Other Notes Receivable (Schedule of Bickford Construction Loans) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	$ 274,700,000
Loans and Leases Receivable, Net Amount	(299,952,000)	$ (292,427,000)
Bickford Note Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	42,900,000
Loans and Leases Receivable, Net Amount	(36,700,000)
June 2020 | Bickford Note Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Amount	$ (7,955,000)