Mortgage Loans Payable and Unsecured Credit Facility (Narrative) (Details) - USD ($)				6 Months Ended
	Jul. 29, 2021	May 05, 2021	Aug. 04, 2020	Jun. 30, 2021	Feb. 11, 2021	Dec. 31, 2020
Line Of Credit Facility [Line Items]
Credit facilities				$ 12,000,000		$ 175,000,000
Approximate amount of accumulated other comprehensive loss to be reclassified into earnings				6,300,000
Interest Rate Swap [Member]
Line Of Credit Facility [Line Items]
Derivative, notional amount				$ 300,000,000.0		$ 425,000,000.0
Non-recourse Mortgage [Member]
Line Of Credit Facility [Line Items]
Non-recourse mortgage amount		$ 114,000,000.0
Maturity date		Jun. 01, 2031
Interest at fixed-rate		3.49%
Unsecured Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility borrowing capacity			$ 300,000,000
Aggregate borrowing capacity including increase under accordion feature			$ 750,000,000
Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility borrowing capacity					$ 112,100,000
Line of credit facility extension allowed period			1 year	1 year
Basis spread on borrowings variable rate				1.65%
Credit facilities					$ 12,000,000.0
Revolving Credit Facility [Member] | Subsequent Event [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate	1.50%
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			$ 250,000,000
Credit facility expiration date			Sep. 08, 2021
Term loan facility [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate				1.60%
Term loan facility [Member] | Subsequent Event [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate	1.45%
Term loan facility [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate			1.30%
Term loan facility [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Basis spread on borrowings variable rate			1.90%
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			Sep. 08, 2022