Disposal group including discontinued operation, land available for development.

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- Definition

Disposal group including discontinued operation, accumulated depreciation.

+ References

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- Definition

Disposal group including discontinued operation, operating real estate investment property, at cost.

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- Definition

Disposal group including discontinued operation, operating real estate investment property, net.

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- Definition

Disposal group including discontinued operation real estate investments.

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- Definition

Amount classified as assets attributable to disposal group held for sale or disposed of.

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Amount classified as inventory attributable to disposal group held for sale or disposed of.

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Amount classified as other liabilities attributable to disposal group held for sale or disposed of.

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Amount classified as liabilities attributable to disposal group held for sale or disposed of.

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Real Estate Investments - Summary of Properties Classified as Held for Sale Included in Continuing Operations (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS HELD FOR SALE
Total assets held for sale, net	$ 11,599	$ 392
Held for Sale Properties Included in Continuing Operations [Member]
ASSETS HELD FOR SALE
Land inventory	11,599
Total real estate investments	11,599		$ 41,718
Total assets held for sale, net	11,599		41,718
Operating properties			73,591
Accumulated depreciation			(32,916)
Operating real estate investments, net			40,675
Land held for development			1,043
LIABILITIES HELD FOR SALE
Other liabilities			81
Total liabilities held for sale			81
Held for Sale Properties Included in Continuing Operations [Member] \| Pennsylvania Suburbs - Land [Member]
ASSETS HELD FOR SALE
Land inventory	4,254
Total real estate investments	4,254
Total assets held for sale, net	4,254
Held for Sale Properties Included in Continuing Operations [Member] \| Metropolitan Washington, D.C. - Office [Member]
ASSETS HELD FOR SALE
Total real estate investments			9,785
Total assets held for sale, net			9,785
Operating properties			21,720
Accumulated depreciation			(11,935)
Operating real estate investments, net			9,785
Land held for development			0
LIABILITIES HELD FOR SALE
Other liabilities			73
Total liabilities held for sale			73
Held for Sale Properties Included in Continuing Operations [Member] \| Other Segment - Office [Member]
ASSETS HELD FOR SALE
Total real estate investments			30,890
Total assets held for sale, net			30,890
Operating properties			51,871
Accumulated depreciation			(20,981)
Operating real estate investments, net			30,890
Land held for development			0
LIABILITIES HELD FOR SALE
Other liabilities			8
Total liabilities held for sale			8
Held for Sale Properties Included in Continuing Operations [Member] \| Other Segment - Land [Member]
ASSETS HELD FOR SALE
Land inventory	7,345
Total real estate investments	7,345		1,043
Total assets held for sale, net	$ 7,345		1,043
Operating properties			0
Accumulated depreciation			0
Operating real estate investments, net			0
Land held for development			1,043
LIABILITIES HELD FOR SALE
Other liabilities			0
Total liabilities held for sale			$ 0