Real Estate (Schedule Of Transactions Related To Properties Held For Sale/Conveyance) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate Properties [Line Items]
Gain on sale		$ 59,000		$ 6,413,000
Upland Square [Member]
Real Estate Properties [Line Items]
Impairment charges on sale of property		6,300,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Real Estate Properties [Line Items]
Sales Price		$ 98,250,000	$ 4,075,000	53,325,000
Gain on sale				$ 6,413,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Blue Mountain Commons Land Parcel [Member]
Real Estate Properties [Line Items]
Date Sold				Oct. 22, 2014
Sales Price				$ 350,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Liberty Marketplace [Member]
Real Estate Properties [Line Items]
Date Sold		Feb. 11, 2016
Sales Price		$ 15,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Upland Square [Member]
Real Estate Properties [Line Items]
Date Sold		Nov. 02, 2016
Sales Price	[1]	$ 83,250,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Kenley Village [Member]
Real Estate Properties [Line Items]
Date Sold			May 28, 2015
Sales Price			$ 2,275,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Circle Plaza [Member]
Real Estate Properties [Line Items]
Date Sold			Jul. 22, 2015
Sales Price			$ 1,800,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Fairview Plaza [Member]
Real Estate Properties [Line Items]
Date Sold				May 27, 2014
Sales Price				$ 12,450,000
Gain on sale				$ 3,810,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Carbondale Plaza [Member]
Real Estate Properties [Line Items]
Date Sold				Jul. 18, 2014
Sales Price				$ 10,700,000
Gain on sale				$ 123,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Virginia Little Creek [Member]
Real Estate Properties [Line Items]
Date Sold				Aug. 22, 2014
Sales Price				$ 9,850,000
Gain on sale				$ 2,209,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Annie Land Plaza [Member]
Real Estate Properties [Line Items]
Date Sold				Sep. 26, 2014
Sales Price				$ 3,500,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Smithfield Plaza [Member]
Real Estate Properties [Line Items]
Date Sold				Oct. 21, 2014
Sales Price				$ 12,350,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | St. James Square [Member]
Real Estate Properties [Line Items]
Date Sold				Nov. 05, 2014
Sales Price				$ 4,125,000
Gain on sale				$ 271,000

[1] The company recorded a $6.3 million impairment charge in connection with the sale of this property