Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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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Fair Value of Assets and Liabilities - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair value of assets and liabilities
Asset impairment charges	$ 12,100,000	$ 0	$ 0	$ 12,087,000
Real estate properties, net		$ 258,391,000	$ 459,421,000
Market Approach Valuation Technique \| Real estate properties held for sale \| Significant Unobservable Inputs (Level 3)
Fair value of assets and liabilities
Fair value of assets	29,700,000
Disposition Plan \| Principal Balance \| Nonrecurring
Fair value of assets and liabilities
Real estate properties, net	$ 41,800,000