Schedule III - Real Estate and Accumulated Depreciation (Details)		12 Months Ended
		Dec. 31, 2019 USD ($) property		Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Gross Leasable Area | property		8,327,916
Initial cost to the Company, Land		$ 295,497,000
Initial cost to the Company, Building and Improvements		905,790,000
Subsequent cost capitalized	[1]	313,919,000
Gross carrying amount of Land		293,456,000
Gross carrying amount of building and improvements		1,221,750,000
SEC Schedule III, Real Estate, Gross, Total		1,515,206,000	[2]	$ 1,508,682,000	$ 1,534,599,000	$ 1,496,429,000
Accumulated Depreciation		$ 389,861,000		$ 361,969,000	$ 341,943,000	$ 313,070,000
Academy Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2001
Percent Owned		100.00%
Gross Leasable Area | property		137,415
Initial cost to the Company, Land		$ 2,406,000
Initial cost to the Company, Building and Improvements		9,623,000
Subsequent cost capitalized	[1]	5,508,000
Gross carrying amount of Land		2,406,000
Gross carrying amount of building and improvements		15,131,000
SEC Schedule III, Real Estate, Gross, Total		17,537,000
Accumulated Depreciation		$ 6,161,000
Academy Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1965
Academy Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Big Y Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2013
Percent Owned		100.00%
Year built/Year last renovated		2007
Gross Leasable Area | property		101,105
Initial cost to the Company, Land		$ 11,272,000
Initial cost to the Company, Building and Improvements		23,395,000
Subsequent cost capitalized	[1]	356,000
Gross carrying amount of Land		10,268,000
Gross carrying amount of building and improvements		24,755,000
SEC Schedule III, Real Estate, Gross, Total		35,023,000
Accumulated Depreciation		$ 4,846,000
Camp Hill [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2002
Percent Owned		100.00%
Gross Leasable Area | property		430,198
Initial cost to the Company, Land		$ 4,460,000
Initial cost to the Company, Building and Improvements		17,857,000
Subsequent cost capitalized	[1]	40,297,000
Gross carrying amount of Land		4,093,000
Gross carrying amount of building and improvements		58,521,000
SEC Schedule III, Real Estate, Gross, Total		62,614,000
Accumulated Depreciation		$ 22,665,000
Camp Hill [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1958
Camp Hill [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2005
Carmans Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		195,485
Initial cost to the Company, Land		$ 8,539,000
Initial cost to the Company, Building and Improvements		35,804,000
Subsequent cost capitalized	[1]	17,679,000
Gross carrying amount of Land		8,421,000
Gross carrying amount of building and improvements		53,601,000
SEC Schedule III, Real Estate, Gross, Total		62,022,000
Accumulated Depreciation		$ 13,224,000
Carmans Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1954
Carmans Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2007
Christina Crossing [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2017
Percent Owned		100.00%
Year built/Year last renovated		2008
Gross Leasable Area | property		119,446
Initial cost to the Company, Land		$ 4,341,000
Initial cost to the Company, Building and Improvements		23,227,000
Subsequent cost capitalized	[1]	1,502,000
Gross carrying amount of Land		4,341,000
Gross carrying amount of building and improvements		24,729,000
SEC Schedule III, Real Estate, Gross, Total		29,070,000
Accumulated Depreciation		$ 2,618,000
Coliseum Marketplace [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		106,648
Initial cost to the Company, Land		$ 2,924,000
Initial cost to the Company, Building and Improvements		14,416,000
Subsequent cost capitalized	[1]	5,616,000
Gross carrying amount of Land		3,586,000
Gross carrying amount of building and improvements		19,370,000
SEC Schedule III, Real Estate, Gross, Total		22,956,000
Accumulated Depreciation		$ 7,930,000
Coliseum Marketplace [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1987
Coliseum Marketplace [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2012
Colonial Commons [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2011
Percent Owned		100.00%
Gross Leasable Area | property		410,432
Initial cost to the Company, Land		$ 9,367,000
Initial cost to the Company, Building and Improvements		37,496,000
Subsequent cost capitalized	[1]	7,812,000
Gross carrying amount of Land		9,367,000
Gross carrying amount of building and improvements		45,308,000
SEC Schedule III, Real Estate, Gross, Total		54,675,000
Accumulated Depreciation		$ 14,817,000
Colonial Commons [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2011
Colonial Commons [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Crossroads II [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2008
Percent Owned		60.00%
Year built/Year last renovated		2009
Gross Leasable Area | property		133,717
Initial cost to the Company, Land		$ 15,383,000
Subsequent cost capitalized	[1]	29,714,000
Gross carrying amount of Land		17,671,000
Gross carrying amount of building and improvements		27,426,000
SEC Schedule III, Real Estate, Gross, Total		45,097,000
Accumulated Depreciation		$ 7,380,000
East River Park [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2015
Percent Owned		100.00%
Gross Leasable Area | property		150,038
Initial cost to the Company, Land		$ 9,143,000
Initial cost to the Company, Building and Improvements		30,893,000
Subsequent cost capitalized	[1]	5,173,000
Gross carrying amount of Land		9,398,000
Gross carrying amount of building and improvements		35,811,000
SEC Schedule III, Real Estate, Gross, Total		45,209,000
Accumulated Depreciation		$ 5,523,000
East River Park [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1946
East River Park [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1996
Elmhurst Square [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2006
Percent Owned		100.00%
Gross Leasable Area | property		66,254
Initial cost to the Company, Land		$ 1,371,000
Initial cost to the Company, Building and Improvements		5,994,000
Subsequent cost capitalized	[1]	1,223,000
Gross carrying amount of Land		1,371,000
Gross carrying amount of building and improvements		7,217,000
SEC Schedule III, Real Estate, Gross, Total		8,588,000
Accumulated Depreciation		$ 2,410,000
Elmhurst Square [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1961
Elmhurst Square [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1983
Fairview Commons [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		52,964
Initial cost to the Company, Land		$ 858,000
Initial cost to the Company, Building and Improvements		3,568,000
Subsequent cost capitalized	[1]	381,000
Gross carrying amount of Land		858,000
Gross carrying amount of building and improvements		3,949,000
SEC Schedule III, Real Estate, Gross, Total		4,807,000
Accumulated Depreciation		$ 1,312,000
Fairview Commons [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1976
Fairview Commons [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2003
Fieldstone Marketplace [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Percent Owned		100.00%
Gross Leasable Area | property		150,123
Initial cost to the Company, Land		$ 5,229,000
Initial cost to the Company, Building and Improvements		21,440,000
Subsequent cost capitalized	[1]	3,269,000
Gross carrying amount of Land		5,167,000
Gross carrying amount of building and improvements		24,771,000
SEC Schedule III, Real Estate, Gross, Total		29,938,000
Accumulated Depreciation		$ 9,926,000
Fieldstone Marketplace [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Year built/Year last renovated		1988
Fieldstone Marketplace [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2012
Year built/Year last renovated		2003
Fishtown Crossing (f/k/a Port Richmond Village) [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2001
Percent Owned		100.00%
Year built/Year last renovated		1988
Gross Leasable Area | property		120,375
Initial cost to the Company, Land		$ 2,942,000
Initial cost to the Company, Building and Improvements		11,769,000
Subsequent cost capitalized	[1]	2,679,000
Gross carrying amount of Land		2,843,000
Gross carrying amount of building and improvements		14,547,000
SEC Schedule III, Real Estate, Gross, Total		17,390,000
Accumulated Depreciation		$ 5,087,000
Franklin Village Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Percent Owned	[3]	100.00%
Gross Leasable Area | property	[3]	303,524
Initial cost to the Company, Land	[3]	$ 14,270,000
Initial cost to the Company, Building and Improvements	[3]	61,915,000
Subsequent cost capitalized	[1],[3]	5,929,000
Gross carrying amount of Land	[3]	14,681,000
Gross carrying amount of building and improvements	[3]	67,433,000
SEC Schedule III, Real Estate, Gross, Total	[3]	82,114,000
Accumulated Depreciation	[3]	$ 16,974,000
Franklin Village Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired	[3]	2004
Year built/Year last renovated	[3]	1987
Franklin Village Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired	[3]	2012
Year built/Year last renovated	[3]	2005
General Booth Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Year built/Year last renovated		1985
Gross Leasable Area | property		71,639
Initial cost to the Company, Land		$ 1,935,000
Initial cost to the Company, Building and Improvements		9,493,000
Subsequent cost capitalized	[1]	(164,000)
Gross carrying amount of Land		1,935,000
Gross carrying amount of building and improvements		9,329,000
SEC Schedule III, Real Estate, Gross, Total		11,264,000
Accumulated Depreciation		$ 3,223,000
Girard Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2019
Percent Owned		100.00%
Gross Leasable Area | property		35,688
Initial cost to the Company, Land		$ 4,685,000
Initial cost to the Company, Building and Improvements		4,648,000
Gross carrying amount of Land		4,685,000
Gross carrying amount of building and improvements		4,648,000
SEC Schedule III, Real Estate, Gross, Total		9,333,000
Accumulated Depreciation		$ 160,000
Glen Allen Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Year built/Year last renovated		2000
Gross Leasable Area | property		63,328
Initial cost to the Company, Land		$ 6,769,000
Initial cost to the Company, Building and Improvements		683,000
Subsequent cost capitalized	[1]	(180,000)
Gross carrying amount of Land		5,367,000
Gross carrying amount of building and improvements		1,905,000
SEC Schedule III, Real Estate, Gross, Total		7,272,000
Accumulated Depreciation		$ 664,000
Gold Star Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2006
Percent Owned		100.00%
Year built/Year last renovated		1988
Gross Leasable Area | property		71,720
Initial cost to the Company, Land		$ 1,644,000
Initial cost to the Company, Building and Improvements		6,519,000
Subsequent cost capitalized	[1]	712,000
Gross carrying amount of Land		1,644,000
Gross carrying amount of building and improvements		7,231,000
SEC Schedule III, Real Estate, Gross, Total		8,875,000
Accumulated Depreciation		$ 3,224,000
Golden Triangle [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		202,790
Initial cost to the Company, Land		$ 2,320,000
Initial cost to the Company, Building and Improvements		9,713,000
Subsequent cost capitalized	[1]	10,661,000
Gross carrying amount of Land		2,320,000
Gross carrying amount of building and improvements		20,374,000
SEC Schedule III, Real Estate, Gross, Total		22,694,000
Accumulated Depreciation		$ 9,818,000
Golden Triangle [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1960
Golden Triangle [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2005
Groton Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Year built/Year last renovated		1969
Gross Leasable Area | property		130,264
Initial cost to the Company, Land		$ 3,070,000
Initial cost to the Company, Building and Improvements		12,320,000
Subsequent cost capitalized	[1]	8,513,000
Gross carrying amount of Land		3,113,000
Gross carrying amount of building and improvements		20,790,000
SEC Schedule III, Real Estate, Gross, Total		23,903,000
Accumulated Depreciation		$ 5,763,000
Halifax Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Year built/Year last renovated		1994
Gross Leasable Area | property		51,510
Initial cost to the Company, Land		$ 1,412,000
Initial cost to the Company, Building and Improvements		5,799,000
Subsequent cost capitalized	[1]	551,000
Gross carrying amount of Land		1,347,000
Gross carrying amount of building and improvements		6,415,000
SEC Schedule III, Real Estate, Gross, Total		7,762,000
Accumulated Depreciation		$ 2,900,000
Hamburg Square [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2004
Percent Owned		100.00%
Gross Leasable Area | property		102,058
Initial cost to the Company, Land		$ 1,153,000
Initial cost to the Company, Building and Improvements		4,678,000
Subsequent cost capitalized	[1]	6,302,000
Gross carrying amount of Land		1,153,000
Gross carrying amount of building and improvements		10,980,000
SEC Schedule III, Real Estate, Gross, Total		12,133,000
Accumulated Depreciation		$ 3,871,000
Hamburg Square [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1993
Hamburg Square [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2010
Jordan Lane [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		177,504
Initial cost to the Company, Land		$ 4,291,000
Initial cost to the Company, Building and Improvements		21,176,000
Subsequent cost capitalized	[1]	883,000
Gross carrying amount of Land		4,291,000
Gross carrying amount of building and improvements		22,059,000
SEC Schedule III, Real Estate, Gross, Total		26,350,000
Accumulated Depreciation		$ 8,143,000
Jordan Lane [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1969
Jordan Lane [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1991
Kempsville Crossing [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		78,162
Initial cost to the Company, Land		$ 2,207,000
Initial cost to the Company, Building and Improvements		11,000,000
Subsequent cost capitalized	[1]	(2,757,000)
Gross carrying amount of Land		2,207,000
Gross carrying amount of building and improvements		8,243,000
SEC Schedule III, Real Estate, Gross, Total		10,450,000
Accumulated Depreciation		$ 3,145,000
Kempsville Crossing [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1985
Kempsville Crossing [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Kings Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		168,243
Initial cost to the Company, Land		$ 2,413,000
Initial cost to the Company, Building and Improvements		12,604,000
Subsequent cost capitalized	[1]	1,688,000
Gross carrying amount of Land		2,408,000
Gross carrying amount of building and improvements		14,297,000
SEC Schedule III, Real Estate, Gross, Total		16,705,000
Accumulated Depreciation		$ 4,007,000
Kings Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1970
Kings Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1994
Lawndale Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2015
Percent Owned		100.00%
Year built/Year last renovated		1998
Gross Leasable Area | property		92,773
Initial cost to the Company, Land		$ 3,635,000
Initial cost to the Company, Building and Improvements		21,854,000
Subsequent cost capitalized	[1]	968,000
Gross carrying amount of Land		3,635,000
Gross carrying amount of building and improvements		22,822,000
SEC Schedule III, Real Estate, Gross, Total		26,457,000
Accumulated Depreciation		$ 4,123,000
Meadows Marketplace [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Percent Owned		100.00%
Year built/Year last renovated		2005
Gross Leasable Area | property		91,518
Initial cost to the Company, Land		$ 1,914,000
Subsequent cost capitalized	[1]	11,648,000
Gross carrying amount of Land		1,914,000
Gross carrying amount of building and improvements		11,648,000
SEC Schedule III, Real Estate, Gross, Total		13,562,000
Accumulated Depreciation		$ 4,019,000
Meadows Marketplace [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2004
Meadows Marketplace [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2012
Metro Square [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2008
Percent Owned		100.00%
Year built/Year last renovated		1999
Gross Leasable Area | property		71,896
Initial cost to the Company, Land		$ 3,121,000
Initial cost to the Company, Building and Improvements		12,341,000
Subsequent cost capitalized	[1]	(221,000)
Gross carrying amount of Land		5,250,000
Gross carrying amount of building and improvements		9,991,000
SEC Schedule III, Real Estate, Gross, Total		15,241,000
Accumulated Depreciation		$ 3,282,000
Newport Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Year built/Year last renovated		1996
Gross Leasable Area | property		64,489
Initial cost to the Company, Land		$ 1,721,000
Initial cost to the Company, Building and Improvements		7,758,000
Subsequent cost capitalized	[1]	555,000
Gross carrying amount of Land		1,682,000
Gross carrying amount of building and improvements		8,352,000
SEC Schedule III, Real Estate, Gross, Total		10,034,000
Accumulated Depreciation		$ 3,682,000
New London Mall [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2009
Percent Owned		100.00%
Gross Leasable Area | property		259,566
Initial cost to the Company, Land		$ 14,891,000
Initial cost to the Company, Building and Improvements		24,967,000
Subsequent cost capitalized	[1]	4,688,000
Gross carrying amount of Land		8,807,000
Gross carrying amount of building and improvements		35,739,000
SEC Schedule III, Real Estate, Gross, Total		44,546,000
Accumulated Depreciation		$ 14,163,000
New London Mall [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1967
New London Mall [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1997
Northside Commons [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2008
Percent Owned		100.00%
Year built/Year last renovated		2009
Gross Leasable Area | property		69,136
Initial cost to the Company, Land		$ 3,332,000
Subsequent cost capitalized	[1]	10,035,000
Gross carrying amount of Land		3,379,000
Gross carrying amount of building and improvements		9,988,000
SEC Schedule III, Real Estate, Gross, Total		13,367,000
Accumulated Depreciation		$ 2,599,000
Norwood Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2006
Percent Owned		100.00%
Gross Leasable Area | property		97,756
Initial cost to the Company, Land		$ 1,874,000
Initial cost to the Company, Building and Improvements		8,453,000
Subsequent cost capitalized	[1]	799,000
Gross carrying amount of Land		1,874,000
Gross carrying amount of building and improvements		9,252,000
SEC Schedule III, Real Estate, Gross, Total		11,126,000
Accumulated Depreciation		$ 3,179,000
Norwood Shopping Center [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1965
Norwood Shopping Center [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Oak Ridge Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2006
Percent Owned		100.00%
Year built/Year last renovated		2000
Gross Leasable Area | property		38,700
Initial cost to the Company, Land		$ 960,000
Initial cost to the Company, Building and Improvements		4,254,000
Subsequent cost capitalized	[1]	440,000
Gross carrying amount of Land		960,000
Gross carrying amount of building and improvements		4,694,000
SEC Schedule III, Real Estate, Gross, Total		5,654,000
Accumulated Depreciation		$ 1,743,000
Oakland Commons [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		90,100
Initial cost to the Company, Land		$ 2,504,000
Initial cost to the Company, Building and Improvements		15,662,000
Subsequent cost capitalized	[1]	(344,000)
Gross carrying amount of Land		2,504,000
Gross carrying amount of building and improvements		15,318,000
SEC Schedule III, Real Estate, Gross, Total		17,822,000
Accumulated Depreciation		$ 5,516,000
Oakland Commons [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1962
Oakland Commons [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Oakland Mills [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		59,308
Initial cost to the Company, Land		$ 1,611,000
Initial cost to the Company, Building and Improvements		6,292,000
Subsequent cost capitalized	[1]	1,197,000
Gross carrying amount of Land		1,611,000
Gross carrying amount of building and improvements		7,489,000
SEC Schedule III, Real Estate, Gross, Total		9,100,000
Accumulated Depreciation		$ 2,950,000
Oakland Mills [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1960
Oakland Mills [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2004
Palmyra Shopping Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		111,051
Initial cost to the Company, Land		$ 1,488,000
Initial cost to the Company, Building and Improvements		6,566,000
Subsequent cost capitalized	[1]	2,008,000
Gross carrying amount of Land		1,488,000
Gross carrying amount of building and improvements		8,574,000
SEC Schedule III, Real Estate, Gross, Total		10,062,000
Accumulated Depreciation		$ 3,506,000
Palmyra Shopping Center [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1960
Palmyra Shopping Center [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2012
Pine Grove Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		86,089
Initial cost to the Company, Land		$ 2,010,000
Initial cost to the Company, Building and Improvements		6,489,000
Subsequent cost capitalized	[1]	1,028,000
Gross carrying amount of Land		2,010,000
Gross carrying amount of building and improvements		7,517,000
SEC Schedule III, Real Estate, Gross, Total		9,527,000
Accumulated Depreciation		$ 3,178,000
Pine Grove Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2001
Pine Grove Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2002
Quartermaster Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2014
Percent Owned		100.00%
Year built/Year last renovated		2004
Gross Leasable Area | property		456,602
Initial cost to the Company, Land		$ 37,031,000
Initial cost to the Company, Building and Improvements		54,210,000
Subsequent cost capitalized	[1]	2,870,000
Gross carrying amount of Land		37,031,000
Gross carrying amount of building and improvements		57,080,000
SEC Schedule III, Real Estate, Gross, Total		94,111,000
Accumulated Depreciation		$ 10,890,000
River View Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		189,032
Initial cost to the Company, Land		$ 9,718,000
Initial cost to the Company, Building and Improvements		40,356,000
Subsequent cost capitalized	[1]	8,587,000
Gross carrying amount of Land		10,872,000
Gross carrying amount of building and improvements		47,789,000
SEC Schedule III, Real Estate, Gross, Total		58,661,000
Accumulated Depreciation		$ 19,081,000
River View Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1991
River View Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1998
San Souci Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2009
Percent Owned		40.00%
Gross Leasable Area | property		264,134
Initial cost to the Company, Land		$ 14,849,000
Initial cost to the Company, Building and Improvements		18,445,000
Subsequent cost capitalized	[1]	5,114,000
Gross carrying amount of Land		13,406,000
Gross carrying amount of building and improvements		25,002,000
SEC Schedule III, Real Estate, Gross, Total		38,408,000
Accumulated Depreciation		$ 12,243,000
San Souci Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1985
San Souci Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1997
Senator Square [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2018
Percent Owned		100.00%
Gross Leasable Area | property		61,691
Initial cost to the Company, Building and Improvements		$ 5,327,000
Subsequent cost capitalized	[1]	356,000
Gross carrying amount of building and improvements		5,683,000
SEC Schedule III, Real Estate, Gross, Total		5,683,000
Accumulated Depreciation		$ 668,000
Senator Square [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1946
Senator Square [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2005
Shoppes at Arts District [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2016
Percent Owned		100.00%
Year built/Year last renovated		2011
Gross Leasable Area | property		35,676
Initial cost to the Company, Land		$ 2,247,000
Initial cost to the Company, Building and Improvements		18,616,000
Subsequent cost capitalized	[1]	68,000
Gross carrying amount of Land		2,247,000
Gross carrying amount of building and improvements		18,684,000
SEC Schedule III, Real Estate, Gross, Total		20,931,000
Accumulated Depreciation		$ 2,665,000
South Philadelphia [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		194,435
Initial cost to the Company, Land		$ 8,222,000
Initial cost to the Company, Building and Improvements		36,314,000
Subsequent cost capitalized	[1]	12,432,000
Gross carrying amount of Land		10,363,000
Gross carrying amount of building and improvements		46,605,000
SEC Schedule III, Real Estate, Gross, Total		56,968,000
Accumulated Depreciation		$ 20,638,000
South Philadelphia [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1950
South Philadelphia [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2003
Southington Center [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		155,842
Initial cost to the Company, Building and Improvements		$ 11,834,000
Subsequent cost capitalized	[1]	1,007,000
Gross carrying amount of building and improvements		12,841,000
SEC Schedule III, Real Estate, Gross, Total		12,841,000
Accumulated Depreciation		$ 5,033,000
Southington Center [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1972
Southington Center [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2000
Swede Square [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		100,816
Initial cost to the Company, Land		$ 2,268,000
Initial cost to the Company, Building and Improvements		6,232,000
Subsequent cost capitalized	[1]	6,475,000
Gross carrying amount of Land		2,272,000
Gross carrying amount of building and improvements		12,703,000
SEC Schedule III, Real Estate, Gross, Total		14,975,000
Accumulated Depreciation		$ 5,947,000
Swede Square [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1980
Swede Square [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2012
The Brickyard [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2004
Percent Owned		100.00%
Gross Leasable Area | property		227,598
Initial cost to the Company, Land		$ 7,632,000
Initial cost to the Company, Building and Improvements		29,308,000
Subsequent cost capitalized	[1]	4,846,000
Gross carrying amount of Land		7,648,000
Gross carrying amount of building and improvements		34,138,000
SEC Schedule III, Real Estate, Gross, Total		41,786,000
Accumulated Depreciation		$ 11,879,000
The Brickyard [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1990
The Brickyard [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2012
The Point [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2000
Percent Owned		100.00%
Gross Leasable Area | property		262,620
Initial cost to the Company, Land		$ 2,700,000
Initial cost to the Company, Building and Improvements		10,800,000
Subsequent cost capitalized	[1]	18,537,000
Gross carrying amount of Land		2,996,000
Gross carrying amount of building and improvements		29,041,000
SEC Schedule III, Real Estate, Gross, Total		32,037,000
Accumulated Depreciation		$ 11,669,000
The Point [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1972
The Point [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2012
The Shops at Bloomfield Station [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2016
Percent Owned		100.00%
Year built/Year last renovated		2015
Gross Leasable Area | property		63,844
Initial cost to the Company, Land		$ 625,000
Initial cost to the Company, Building and Improvements		17,674,000
Subsequent cost capitalized	[1]	354,000
Gross carrying amount of Land		625,000
Gross carrying amount of building and improvements		18,028,000
SEC Schedule III, Real Estate, Gross, Total		18,653,000
Accumulated Depreciation		$ 2,147,000
The Shops at Suffolk Downs [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		121,187
Initial cost to the Company, Land		$ 7,580,000
Initial cost to the Company, Building and Improvements		11,089,000
Subsequent cost capitalized	[1]	10,449,000
Gross carrying amount of Land		7,580,000
Gross carrying amount of building and improvements		21,538,000
SEC Schedule III, Real Estate, Gross, Total		29,118,000
Accumulated Depreciation		$ 7,303,000
The Shops at Suffolk Downs [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2005
The Shops at Suffolk Downs [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2011
Timpany Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		182,799
Initial cost to the Company, Land		$ 3,412,000
Initial cost to the Company, Building and Improvements		19,240,000
Subsequent cost capitalized	[1]	1,861,000
Gross carrying amount of Land		3,368,000
Gross carrying amount of building and improvements		21,145,000
SEC Schedule III, Real Estate, Gross, Total		24,513,000
Accumulated Depreciation		$ 6,348,000
Timpany Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1970
Timpany Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1989
Trexler Mall [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2005
Percent Owned		100.00%
Gross Leasable Area | property		337,297
Initial cost to the Company, Land		$ 6,932,000
Initial cost to the Company, Building and Improvements		32,815,000
Subsequent cost capitalized	[1]	9,466,000
Gross carrying amount of Land		6,932,000
Gross carrying amount of building and improvements		42,281,000
SEC Schedule III, Real Estate, Gross, Total		49,213,000
Accumulated Depreciation		$ 15,669,000
Trexler Mall [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1973
Trexler Mall [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2013
Trexlertown Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2006
Percent Owned		100.00%
Gross Leasable Area | property		325,171
Initial cost to the Company, Land		$ 13,349,000
Initial cost to the Company, Building and Improvements		23,867,000
Subsequent cost capitalized	[1]	30,644,000
Gross carrying amount of Land		13,351,000
Gross carrying amount of building and improvements		54,509,000
SEC Schedule III, Real Estate, Gross, Total		67,860,000
Accumulated Depreciation		$ 13,220,000
Trexlertown Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1990
Trexlertown Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2011
Valley Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2003
Percent Owned		100.00%
Gross Leasable Area | property		190,939
Initial cost to the Company, Land		$ 1,950,000
Initial cost to the Company, Building and Improvements		7,766,000
Subsequent cost capitalized	[1]	1,874,000
Gross carrying amount of Land		1,950,000
Gross carrying amount of building and improvements		9,640,000
SEC Schedule III, Real Estate, Gross, Total		11,590,000
Accumulated Depreciation		$ 4,145,000
Valley Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1975
Valley Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1994
Washington Center Shoppes [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2001
Percent Owned		100.00%
Gross Leasable Area | property		157,394
Initial cost to the Company, Land		$ 2,061,000
Initial cost to the Company, Building and Improvements		7,314,000
Subsequent cost capitalized	[1]	5,522,000
Gross carrying amount of Land		2,000,000
Gross carrying amount of building and improvements		12,897,000
SEC Schedule III, Real Estate, Gross, Total		14,897,000
Accumulated Depreciation		$ 5,921,000
Washington Center Shoppes [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1979
Washington Center Shoppes [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1995
Webster Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		98,984
Initial cost to the Company, Land		$ 3,551,000
Initial cost to the Company, Building and Improvements		18,412,000
Subsequent cost capitalized	[1]	4,035,000
Gross carrying amount of Land		4,082,000
Gross carrying amount of building and improvements		21,916,000
SEC Schedule III, Real Estate, Gross, Total		25,998,000
Accumulated Depreciation		$ 6,668,000
Webster Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1960
Webster Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2004
Yorktowne Plaza [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year acquired		2007
Percent Owned		100.00%
Gross Leasable Area | property		138,843
Initial cost to the Company, Land		$ 5,940,000
Initial cost to the Company, Building and Improvements		25,505,000
Subsequent cost capitalized	[1]	1,676,000
Gross carrying amount of Land		5,801,000
Gross carrying amount of building and improvements		27,320,000
SEC Schedule III, Real Estate, Gross, Total		33,121,000
Accumulated Depreciation		$ 9,824,000
Yorktowne Plaza [Member] | Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		1970
Yorktowne Plaza [Member] | Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Year built/Year last renovated		2000
Other [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Percent Owned		100.00%
Initial cost to the Company, Land		$ 1,965,000
Subsequent cost capitalized	[1]	1,598,000
Gross carrying amount of Land		877,000
Gross carrying amount of building and improvements		2,686,000
SEC Schedule III, Real Estate, Gross, Total		3,563,000
Accumulated Depreciation		$ 172,000

[1] Negative amounts represent write-offs of fully depreciated assets.

[2] At December 31, 2019, the aggregate cost for federal income tax purposes was approximately $5.7 million greater than the Company's recorded values.

[3] Amount of encumbrance totals $46.7 million at December 31, 2019.