Organization And Summary Of Significant Accounting Policies (Narrative) (Detail) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended				12 Months Ended
	Jul. 28, 2014 USD ($)	Jul. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Property State $ / shares shares	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Property Segment State $ / shares shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Impairment Of Assets							$ 140,318	$ 19,695	$ 29,966
Quantifying Misstatement in Current Year Financial Statements, Amount			$ 6,200
Line of credit facilities gross borrowings							310,000	140,000	512,500
Line of credit facilities gross repayments							$ 245,000	270,000	382,500
Number of properties | Property			33				33
Number of states where the properties located | State			11				11
Number of states where the properties operated | State			10				10
Long Lived Assets Held-for-sale, Description			The above property counts do not include Gadsden Mall in Gadsden, Alabama, Lycoming Mall in Pennsdale, Pennsylvania, New River Valley Mall in Christiansburg, Virginia, Palmer Park Mall in Easton, Pennsylvania, Wiregrass Commons Mall in Dothan, Alabama and two street retail properties in Philadelphia, Pennsylvania because these properties have been classified as “held for sale” as of December 31, 2015. Palmer Park Mall was sold in February 2016.
Interest in the Operating Partnership			89.20%				89.20%
Amount available for distribution			$ 182,400				$ 182,400
Closing share price | $ / shares			$ 21.87				$ 21.87
Number of outstanding OP units held by limited partners | shares			8,338,299				8,338,299
Number of reportable segment | Segment							1
Percentage of consolidated revenue having no single tenants							10.00%
Cash and cash equivalents			$ 22,855				$ 22,855	40,433	34,230		$ 33,990
Tenant security deposits			3,700				3,700	3,500
Cash paid for interest including interest of discontinued operations							76,500	76,600	94,100
Capitalized interest							1,900	600	900
Accrued construction costs							$ (1,600)	(2,000)	2,400
Revenue from tenant rent and other tenant-related activities							95.00%
Straight line rent adjustments							$ 2,000	1,500	1,400
Straight-line rent receivable			22,400				22,400	23,700
Account receivable included in accrued income			40,324				40,324	$ 40,566
Holding period of properties								10 years
Goodwill			5,249				$ 5,249	$ 5,662	5,662	$ 7,156
Amortization of above-market and below-market lease intangibles									$ 1,000
Income tax benefit recognition criteria percentage threshold, minimum							50.00%
Net deferred tax assets			25,600				$ 25,600	22,700
Accrued Income Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Account receivable included in accrued income			$ 3,200				$ 3,200	$ 3,400
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Partnership investment, ownership interest			25.00%				25.00%
Terminal capitalization rate							4.50%	5.25%	6.25%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Partnership investment, ownership interest			50.00%				50.00%
Terminal capitalization rate							15.50%	12.50%	12.00%
Metroplex Shopping Center [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties | Property			25				25
Power Center [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties | Property			4				4
Development Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties | Property			4				4
Mixed use development properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties | Property			2				2
Other development properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties | Property			1				1
Mall [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of properties sold | Property							2
Paxton Towne Centre [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill divested								$ 700
Christiana Center [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill divested			$ 800				$ 800
Value of in-place lease intangibles [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization of in-place lease intangibles							1,900	1,600	$ 1,600
Above/(Below) Market Leases [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization of above-market and below-market lease intangibles							300	$ 1,000
Gadsden Mall, New River Valley Mall and Wiregrass Commons Mall [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment Of Assets					$ 36,600		$ 63,904
Springfield Town Center [Member]
Summary Of Significant Accounting Policies [Line Items]
Other significant noncash transaction, consideration given, OP Units				6,250,000		6,250,000
Other Significant Noncash Transaction, Value of Consideration Given				$ 145,200		$ 145,200
The Gallery at Market East [Member]
Summary Of Significant Accounting Policies [Line Items]
Real Estate Property Sales Price	$ 106,900	$ 106,800