Number of unconsolidated investments in Real Estate Ventures.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Area of land held.

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- Definition

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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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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- Definition

Net rentable area for properties owned.

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The number of real estate properties owned as of the balance sheet date.

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The number of units in a real estate property owned as of the balance sheet date.

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Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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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 Real Estate Ventures - Textual (Details) $ in Thousands, ft² in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) a ft² investment apartment property	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) a ft² investment apartment property	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of properties \| property	94		94
Investment in Real Estate Ventures	$ 118,558		$ 118,558		$ 120,294
Accounts receivable	$ 18,823		$ 18,823		16,363
Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15.00%		15.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%		70.00%
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable	$ 800		$ 800		$ 800
Real Estate Venture \| Management Fees
Schedule of Equity Method Investments [Line Items]
Service and other revenue	800	$ 1,100	2,000	$ 2,200
Real Estate Venture \| Leasing Commission Income
Schedule of Equity Method Investments [Line Items]
Service and other revenue	200	$ 300	600	$ 500
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment in Real Estate Ventures	$ 113,100		$ 113,100
Unconsolidated Real Estate Ventures \| Office properties
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| investment	3		3
Rentable area (in square feet) \| ft²	5.4		5.4
Unconsolidated Real Estate Ventures \| Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of properties \| property	7		7
Unconsolidated Real Estate Ventures \| Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| investment	2		2
Area of land (in acres) \| a	1.4		1.4
Unconsolidated Real Estate Ventures \| Land Under Active Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| investment	1		1
Area of land (in acres) \| a	1.3		1.3
Unconsolidated Real Estate Ventures \| Residential Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| investment	1		1
Number of apartment units (in units) \| apartment	321		321