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Equity Investment Basis Adjustment, Amortization Period

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Equity Method Investment, Summarized Financial Information, Impairments

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Investments in Affiliates, Subsidiaries, Associates, and Joint Ventures, Properties Contributed

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Number Of Retail Properties Sold

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Number of Retail Properties

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The charge against earnings resulting from the aggregate write down of assets from their carrying value to their fair value. Includes charges from both continued and discontinued operations.

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Area of a real estate property.

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Amount of gain on the sale of property that does not qualify for gain recognition as of the balance sheet date.

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Fixed interest rate related to the interest rate derivative.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Nominal or face amount used to calculate payment on derivative.

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The number of derivative instruments of a particular group held by the entity.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Amount of gain (loss) on sale or disposal of an equity method investment.

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Gross amount of debt extinguished.

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

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Amount of investment in equity method investee and investment in and advance to affiliate.

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The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or sale of an entity that is related to it but not strictly controlled.

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Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

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The cash outflow for a borrowing supported by a written promise to pay an obligation.

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Line items represent financial 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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Investment in Unconsolidated Entities - Narrative (Details)			12 Months Ended
	Jun. 24, 2019 USD ($)	Apr. 17, 2013 USD ($)	Dec. 31, 2020 USD ($) ft² derivative_instrument property	Dec. 31, 2019 USD ($) ft²	Dec. 31, 2018 USD ($) property	Jan. 01, 2018 USD ($)	Dec. 31, 2013 property
Variable Interest Entity [Line Items]
Investment in unconsolidated entities			$ 109,051,000	$ 118,861,000
Proceeds from the sale and transfer of investment properties, net			8,027,000	346,707,000	$ 430,514,000
Provision for asset impairment			9,002,000	2,359,000	3,510,000
IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Repayment of mortgage note payable on one retail property			14,872,000
Retail
Variable Interest Entity [Line Items]
Proceeds from the sale and transfer of investment properties, net					2,274,000
Purchase price			42,247,000	$ 365,764,000
Equity method investment, Impairments			$ 6,059,000
Square Feet \| ft²			237,822	977,400
Provision for asset impairment					2,020,000
Retail \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Gain (loss) on sale of real estate, net					(4,135,000)
Equity method investment, Impairments					$ 3,673,000
Number of retail properties \| property			1		3
Number of retail properties sold \| property					2
Rockwell Plaza \| Retail
Variable Interest Entity [Line Items]
Gain (loss) on sale of real estate, net				$ (307,000)
Equity method investment, Impairments				794,000
Rockwell Plaza \| Retail \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Proceeds from the sale and transfer of investment properties, net				20,500,000
Gain (loss) on sale of real estate, net				(559,000)
Equity method investment, Impairments				$ 1,443,000
Square Feet \| ft²				255,000
IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Ownership percentage			55.00%	55.00%
Investment in unconsolidated entities				$ 118,861,000
Amortization period			30 years
Aggregate deferred gain			$ 958,000
Gain (loss) on sale of real estate, net			1,741,000
IAGM Retail Fund I, LLC \| Retail
Variable Interest Entity [Line Items]
Equity method investment, Impairments			11,015,000
Interest Rate Swap
Variable Interest Entity [Line Items]
Derivative liability			$ 289,000
Interest Rate Swap \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Number of derivatives held \| derivative_instrument			2
Derivative liability			$ 525,000
Interest Rate Swap, Effective Date April 1, 2020, 1.979% Fixed Interest \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Notional amount			$ 45,000
Fixed interest rate			1.979%
Interest Rate Swap, Effective Date April 1, 2020, 1.956% Fixed Interest \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Notional amount			$ 30,000
Fixed interest rate			1.956%
Unconsolidated Entities \| Downtown Railyard Venture, LLC
Variable Interest Entity [Line Items]
Investment in unconsolidated entities, impairment loss				29,933,000
Proceeds from divestiture	$ 30,000,000
Realized gain (loss) on disposal				0
Unconsolidated Entities \| IAGM Retail Fund I, LLC
Variable Interest Entity [Line Items]
Number of retail properties contributed \| property							14
Proceeds from the sale and transfer of investment properties, net		$ 15,625,000
Amortization period		30 years
Aggregate deferred gain						$ 12,756,000
Antoine Town Center
Variable Interest Entity [Line Items]
Aggregate deferred gain			$ 54,000
Antoine Town Center \| Retail
Variable Interest Entity [Line Items]
Purchase price			$ 22,254,000
Square Feet \| ft²			110,500
Mortgages
Variable Interest Entity [Line Items]
Debt extinguished				$ 16,250,000