Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of Variable Interest Entities Consolidated

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- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before accumulated depreciation of fixtures and equipment. Includes, but is not limited to, machinery, equipment, and engines.

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- Definition

The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

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Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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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.

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

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Real Estate Held for Sale in Consolidated VIEs (Details)		1 Months Ended	12 Months Ended
	Mar. 31, 2017 variable_interest_entity	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Investment [Line Items]
Real estate held for sale before accumulated depreciation and amortization			$ 29,704,000	$ 64,202,000
Riverchase Landing and The Clusters
Investment [Line Items]
Number of consolidated VIEs \| variable_interest_entity	2
Riverchase Landing \| VIE, Primary Beneficiary
Investment [Line Items]
Gains on sales of real estate investment		$ 2,300,000
Land			2,650,000	7,000,000
Building and improvements			26,032,000	53,468,000
Furniture, fixtures and equipment			974,000	2,150,000
Lease intangible			2,802,000	5,340,000
Real estate held for sale before accumulated depreciation and amortization			32,458,000	67,958,000
Accumulated depreciation			(418,000)	(647,000)
Accumulated amortization of lease intangible			(2,336,000)	(3,109,000)
Real estate held for sale in consolidated variable interest entities			29,704,000	64,202,000
Depreciation			0	600,000
Amortization			$ 0	$ 3,100,000