Real Estate (Held For Sale) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 property	Dec. 31, 2013 property	Dec. 31, 2012 property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties classified as held for sale	7	8
Land and improvements	3,246us-gaap_InventoryLandHeldForSale	5,751us-gaap_InventoryLandHeldForSale
Building and improvements	4,644nnn_InventoryBuildingHeldForSale	8,067nnn_InventoryBuildingHeldForSale
Real Estate Held-for-sale	7,890us-gaap_RealEstateHeldforsale	13,818us-gaap_RealEstateHeldforsale
Less impairment	(1,022)	(2,132)
Inventory, Real Estate, Held-for-sale	5,395us-gaap_InventoryRealEstateHeldForSale	9,324us-gaap_InventoryRealEstateHeldForSale
Assets Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Less accumulated depreciation and amortization	(1,473)	(2,362)
Assets Held-for-sale \| Discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of sold properties	2	35	34

Accumulated Impairment Real Estate Held For Sale

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- Definition

Inventory, Building, Held-for-sale

+ References

No definition available.

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- Definition

Number Of Disposed Properties Discontinued Operations

+ References

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- Definition

Number Of Properties Classified As Held For Sale

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of parcels of land held for sale, and on which the entity has no intention or no further intention to perform construction activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

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- Definition

Represents properties which were acquired directly or through foreclosure for which a committed plan to sell exists and an active program to market such properties has been initiated.

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of investments in land and buildings held for sale, excluding real estate considered to be inventory of the entity.

+ References

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- Definition

The cumulative amount of depreciation for real estate property held for investment purposes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(3))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 7

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