Real Estate Activities - Disposition (Details) $ in Thousands	1 Months Ended					3 Months Ended		6 Months Ended	9 Months Ended
	Jun. 30, 2023 USD ($)	Feb. 28, 2023 USD ($)	Sep. 30, 2022 USD ($) Outparcels	Aug. 31, 2022 USD ($) Outparcels	Feb. 28, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate						$ 60	$ 7,509		$ 60	$ 9,210
Number of outparcels sold | Outparcels			3	2
Proceeds from redemption of preferred equity					$ 2,500
Cash proceeds from sales of real estate									29,713	39,515
Gain on sale of preferred equity interest						$ 0	0		0	3,688
Plymouth Meeting Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, consideration		$ 27,000
Cash proceeds from sales of real estate		$ 26,300
Woodland Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate									$ 1,100
Disposal group, consideration	$ 4,800
Cash proceeds from sales of real estate	$ 3,400
Moorestown Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate			$ 1,800							8,800
Disposal group, consideration			3,400				3,400	$ 11,800		3,400
Cash proceeds from sales of real estate			3,100					11,700
The Mall at Prince Georges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate			4,600
Disposal group, consideration			8,500	$ 2,400			$ 8,500			8,500
Cash proceeds from sales of real estate			$ 8,200
Magnolia Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, consideration				900
The Mall at Prince George's and Magnolia Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate				2,800
Cash proceeds from sales of real estate				$ 3,200
Francis Scott Key Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of interests in real estate										$ 1,700
Disposal group, consideration								2,400
Cash proceeds from sales of real estate								$ 2,400