Investment In Real Estate Joint Ventures And Partnerships (Narrative) (Details) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 02, 2021 USD ($) Center	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) Center	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) Center
Schedule of Equity Method Investments [Line Items]
Net basis differentials for equity method investments		$ 10,700	$ 10,500		$ 10,500		$ 10,700
Joint venture fee income			$ 1,300	$ 1,100	$ 2,900	$ 2,700
Number of centers sold | Center	1				4
Proceeds from sale of property	$ 43,800				$ 71,400
Gain on sale of property					9,611	21,474
Acquisition of real estate property					5,200
Real estate joint ventures and partnerships - Investments					$ 2,075	4,391
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures		20.00%	20.00%		20.00%		20.00%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures		90.00%	90.00%		90.00%		90.00%
COVID-19 [Member]
Schedule of Equity Method Investments [Line Items]
Net recoveries of adjustments to revenue related to potentially uncollectible revenues and disputed amounts			$ 1,200		$ 2,900
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts				19,300		28,700
Entity's share of the adjustment to revenue related to potentially uncollectible revenues and disputed amounts				1,700
Straight Line Rent Receivables [Member]
Schedule of Equity Method Investments [Line Items]
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts				4,800		12,400
Entity's share of the adjustment to revenue related to potentially uncollectible revenues and disputed amounts				400
Disposal Group, Multiple Centers [Member]
Schedule of Equity Method Investments [Line Items]
Number of centers sold | Center							2
Number of centers sold the Entity had interest in | Center							2
Proceeds From divestitures							$ 148,300
Gain on sale of property							$ 23,500
Disposal Group, Multiple Centers [Member] | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures		20.00%					20.00%
Disposal Group, Multiple Centers [Member] | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures		50.00%					50.00%
Investment Mixed Use New Development [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures		90.00%					90.00%
Real estate joint ventures and partnerships - Investments							$ 8,700
Unconsolidated joint venture
Schedule of Equity Method Investments [Line Items]
Variable-rate debt			170,000		170,000
Unconsolidated joint venture | COVID-19 [Member]
Schedule of Equity Method Investments [Line Items]
Net recoveries of adjustments to revenue related to potentially uncollectible revenues and disputed amounts			300		1,000
Entity's share of net recoveries of adjustments to revenue related to potentially uncollectible revenues and disputed amount			$ 100		$ 200
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts				5,100		5,900
Entity's share of the adjustment to revenue related to potentially uncollectible revenues and disputed amounts						2,000
Unconsolidated joint venture | Straight Line Rent Receivables [Member]
Schedule of Equity Method Investments [Line Items]
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts				$ 1,700		2,600
Entity's share of the adjustment to revenue related to potentially uncollectible revenues and disputed amounts						$ 700
Unconsolidated joint venture | Exercised Renewal Option [Member]
Schedule of Equity Method Investments [Line Items]
Period of debt extension (in years)					1 year
Unconsolidated joint venture | Outstanding Renewal Option [Member]
Schedule of Equity Method Investments [Line Items]
Period of debt extension (in years)					1 year
Unconsolidated joint venture | Partnership interest
Schedule of Equity Method Investments [Line Items]
Ownership of joint venture percentage		42.25%					42.25%
Acquisition of real estate property		$ 115,200
Unconsolidated joint venture | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures	20.00%
Proceeds from sale of property	$ 25,500