Mortgage Loans Payable and Unsecured Credit Facility (Narrative) (Details)			6 Months Ended
	Aug. 30, 2021 USD ($) Term	May 05, 2021 USD ($)	Jun. 30, 2022 USD ($) Term	Dec. 31, 2021 USD ($)
Line Of Credit Facility [Line Items]
Credit facilities			$ 41,000,000	$ 66,000,000
Interest Rate Swap [Member]
Line Of Credit Facility [Line Items]
Derivative, notional amount			300,000,000.0	$ 300,000,000.0
Interest Rate Swap [Member] | Discontinued Operations [Member]
Line Of Credit Facility [Line Items]
Interest rate swaps termination benefit			$ 3,400,000
Non-recourse Mortgage [Member]
Line Of Credit Facility [Line Items]
Maturity date		Jun. 01, 2031
Interest at fixed-rate		3.49%
Non-recourse Mortgage [Member] | Nonrecourse
Line Of Credit Facility [Line Items]
Non-recourse mortgage amount		$ 114,000,000.0
Unsecured Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 300,000,000
Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Line of credit facility extension allowed term | Term			2
Line of credit facility extension allowed period			1 year
Basis spread on borrowings variable rate			1.50%
Credit facilities			$ 41,000,000.0
Revolving Credit Facility [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate	1.35%
Revolving Credit Facility [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate	1.95%
Revolving Credit Facility [Member] | Unsecured Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 185,000,000
Credit facility expiration date	Aug. 31, 2024
Line of credit facility extension allowed term | Term	2
Line of credit facility extension allowed period	1 year
Term loan facility [Member] | Unsecured Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 50,000,000
Credit facility expiration date	Aug. 31, 2026
Line of credit facility extension allowed period	4 years