Schedule III - Summary of Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 345,423
Initial Cost of Building & Improvements	1,411,148
Cost of Improvements Net of Retirements and Impairment Charges	1,183,090
Balance of Land and Land Held for Development	389,930
Balance of Building & Improvements and Construction in Progress	2,549,731
Accumulated Depreciation Balance	1,370,065	$ 1,405,260	$ 1,308,427
Current Encumbrance	751,461
Capital City Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	11,380
Initial Cost of Building & Improvements	65,575
Cost of Improvements Net of Retirements and Impairment Charges	61,471
Balance of Land and Land Held for Development	11,325
Balance of Building & Improvements and Construction in Progress	127,101
Accumulated Depreciation Balance	$ 65,874
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Cherry Hill Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 29,938
Initial Cost of Building & Improvements	185,611
Cost of Improvements Net of Retirements and Impairment Charges	257,064
Balance of Land and Land Held for Development	48,610
Balance of Building & Improvements and Construction in Progress	424,003
Accumulated Depreciation Balance	290,914
Current Encumbrance	$ 243,675
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Dartmouth Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 7,015
Initial Cost of Building & Improvements	28,323
Cost of Improvements Net of Retirements and Impairment Charges	55,416
Balance of Land and Land Held for Development	12,021
Balance of Building & Improvements and Construction in Progress	78,733
Accumulated Depreciation Balance	52,397
Current Encumbrance	$ 53,727
Date of Acquisition/ Construction	1998
Life of Depre- ciation	40 years
Francis Scott Key Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 9,786
Initial Cost of Building & Improvements	47,526
Cost of Improvements Net of Retirements and Impairment Charges	39,295
Balance of Land and Land Held for Development	9,155
Balance of Building & Improvements and Construction in Progress	87,452
Accumulated Depreciation Balance	50,821
Current Encumbrance	$ 52,458
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Jacksonville Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 9,188
Initial Cost of Building & Improvements	47,139
Cost of Improvements Net of Retirements and Impairment Charges	36,814
Balance of Land and Land Held for Development	9,913
Balance of Building & Improvements and Construction in Progress	83,228
Accumulated Depreciation Balance	$ 47,379
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Magnolia Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 6,229
Initial Cost of Building & Improvements	42,302
Cost of Improvements Net of Retirements and Impairment Charges	57,354
Balance of Land and Land Held for Development	14,368
Balance of Building & Improvements and Construction in Progress	91,517
Accumulated Depreciation Balance	$ 57,972
Date of Acquisition/ Construction	1998
Life of Depre- ciation	40 years
Monroe Land
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 262
Cost of Improvements Net of Retirements and Impairment Charges	$ (262)
Date of Acquisition/ Construction	2006
Moorestown Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 10,934
Initial Cost of Building & Improvements	64,746
Cost of Improvements Net of Retirements and Impairment Charges	100,512
Balance of Land and Land Held for Development	18,899
Balance of Building & Improvements and Construction in Progress	156,847
Accumulated Depreciation Balance	$ 87,323
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Patrick Henry Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 16,075
Initial Cost of Building & Improvements	86,643
Cost of Improvements Net of Retirements and Impairment Charges	55,359
Balance of Land and Land Held for Development	16,398
Balance of Building & Improvements and Construction in Progress	141,679
Accumulated Depreciation Balance	85,384
Current Encumbrance	$ 83,079
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Plymouth Meeting Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 26,984
Initial Cost of Building & Improvements	58,388
Cost of Improvements Net of Retirements and Impairment Charges	55,969
Balance of Land and Land Held for Development	5,055
Balance of Building & Improvements and Construction in Progress	142,648
Accumulated Depreciation Balance	$ 94,518
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
The Mall at Prince Georges
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 23,247
Initial Cost of Building & Improvements	57,686
Cost of Improvements Net of Retirements and Impairment Charges	61,174
Balance of Land and Land Held for Development	7,117
Balance of Building & Improvements and Construction in Progress	130,128
Accumulated Depreciation Balance	$ 79,096
Date of Acquisition/ Construction	1998
Life of Depre- ciation	40 years
Springfield Town Center
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 119,912
Initial Cost of Building & Improvements	353,551
Cost of Improvements Net of Retirements and Impairment Charges	25,534
Balance of Land and Land Held for Development	119,911
Balance of Building & Improvements and Construction in Progress	379,086
Accumulated Depreciation Balance	$ 106,380
Date of Acquisition/ Construction	2015
Life of Depre- ciation	40 years
Swedes Square Land
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 189
Cost of Improvements Net of Retirements and Impairment Charges	36
Balance of Land and Land Held for Development	$ 225
Date of Acquisition/ Construction	2004
Valley Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 8,325
Initial Cost of Building & Improvements	57,931
Cost of Improvements Net of Retirements and Impairment Charges	83,511
Balance of Land and Land Held for Development	23,999
Balance of Building & Improvements and Construction in Progress	125,768
Accumulated Depreciation Balance	$ 62,667
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Viewmont Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 12,505
Initial Cost of Building & Improvements	61,519
Cost of Improvements Net of Retirements and Impairment Charges	48,330
Balance of Land and Land Held for Development	12,598
Balance of Building & Improvements and Construction in Progress	109,756
Accumulated Depreciation Balance	63,261
Current Encumbrance	$ 67,185
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Willow Grove Park
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 26,748
Initial Cost of Building & Improvements	131,189
Cost of Improvements Net of Retirements and Impairment Charges	112,377
Balance of Land and Land Held for Development	36,537
Balance of Building & Improvements and Construction in Progress	233,777
Accumulated Depreciation Balance	126,094
Current Encumbrance	$ 145,237
Date of Acquisition/ Construction	2003
Life of Depre- ciation	40 years
Woodland Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land	$ 26,706
Initial Cost of Building & Improvements	123,019
Cost of Improvements Net of Retirements and Impairment Charges	133,136
Balance of Land and Land Held for Development	43,799
Balance of Building & Improvements and Construction in Progress	238,008
Accumulated Depreciation Balance	99,985
Current Encumbrance	$ 106,100
Date of Acquisition/ Construction	2005
Life of Depre- ciation	40 years