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Area of a real estate property.

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Disposition of Properties and Assets Held for Sale (Details)						3 Months Ended			9 Months Ended
	Jan. 26, 2024 USD ($) property	Dec. 06, 2023 USD ($)	Oct. 26, 2023 USD ($)	Aug. 09, 2023 USD ($) property	Mar. 10, 2023 USD ($) property	Sep. 30, 2024 USD ($) ft²	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($) ft²	Sep. 30, 2024 USD ($) ft²	Sep. 30, 2023 USD ($) ft²	Dec. 31, 2023 USD ($)
Dispositions of Property
Assets held for sale						$ 32,926,000			$ 32,926,000		$ 73,318,000
Area of property (in square feet) \| ft²						5,180,158		6,206,460	5,180,158	6,206,460
Operating results for discontinued operations:
Rental revenue						$ 1,309,000		$ 7,925,000	$ 7,001,000	$ 23,842,000
Rental operating expenses						(643,000)		(2,747,000)	(2,799,000)	(7,673,000)
Real estate taxes and insurance						196,000		(1,027,000)	(295,000)	(3,292,000)
Depreciation and amortization								(1,895,000)	(832,000)	(7,916,000)
Income from dispositions and assets held for sale						862,000		2,256,000	3,075,000	4,961,000
Property in Miami, Florida
Dispositions of Property
Expected sales price								68,000,000.0
Expected loss								19,200,000		19,200,000
Property in Atlanta, Georgia
Dispositions of Property
Sale price						34,000,000.0
Expected sales price								40,000,000.0
Expected loss								20,500,000		$ 20,500,000
Increase in expected loss						6,600,000
Assets held for sale						32,900,000			32,900,000		39,000,000.0
Real estate assets						52,800,000			52,800,000		52,200,000
Straight line rents receivable						4,400,000			$ 4,400,000		$ 2,900,000
Properties in Miami, Florida and Atlanta, Georgia
Dispositions of Property
Impairment charge								39,700,000
Property in Plano, Texas
Dispositions of Property
Sale price								48,000,000.0
Gain (loss) on sale of property								10,600,000
Disposal group disposed of by sale \| Office Property in Elk Grove Village, Illinois
Dispositions of Property
Number of properties sold \| property					1
Sale price					$ 29,100,000
Gain (loss) on sale of property					$ 8,400,000
Disposal group disposed of by sale \| Office property in Charlotte, North Carolina
Dispositions of Property
Number of properties sold \| property				1
Sale price				$ 9,200,000
Gain (loss) on sale of property				$ (800,000)
Disposal group disposed of by sale \| Property in Addison, Texas
Dispositions of Property
Gain (loss) on sale of property								$ 53,000
Area of property (in square feet) \| ft²								7,826		7,826
Disposal group disposed of by sale \| Property in Miami, Florida
Dispositions of Property
Gain (loss) on sale of property		$ (18,900,000)
Disposal group disposed of by sale \| Property in Plano, Texas
Dispositions of Property
Gain (loss) on sale of property			$ 10,600,000
Disposal group disposed of by sale \| Properties In Richardson, Texas
Dispositions of Property
Number of properties sold \| property	1
Sale price	$ 35,000,000.0
Gain (loss) on sale of property	$ (2,100,000)
Additional costs related to sale							$ 5,000
Disposal group disposed of by sale \| Property in Glen Allen, Virginia
Dispositions of Property
Sale price						31,000,000.0
Gain (loss) on sale of property						(13,200,000)
Repayment of outstanding indebtedness						$ 25,300,000
Percentage of proceeds from disposition used for repayment of debt						90.00%			90.00%
Additional cost on sale of properties						$ 700,000