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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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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Net rentable area for properties owned.

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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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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) $ in Thousands, ft² in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) a ft² investment apartment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Schedule of Equity Method Investments [Line Items]
Investment in Real Estate Ventures, equity method	$ 120,294	$ 169,100	$ 194,621
Accounts receivable	16,363	16,394
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable	800
Real Estate Venture \| Management Fees
Schedule of Equity Method Investments [Line Items]
Service and other revenue	4,300	6,300	6,400
Real Estate Venture \| Leasing Commission Income
Schedule of Equity Method Investments [Line Items]
Service and other revenue	1,700	$ 2,500	$ 4,500
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment in Real Estate Ventures, equity method	$ 120,300
Unconsolidated Real Estate Ventures \| Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15.00%
Unconsolidated Real Estate Ventures \| Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Unconsolidated Real Estate Ventures \| Six Real Estate Ventures \| Office Properties
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments In real estate ventures \| investment	3
Rentable square feet \| ft²	5.4
Unconsolidated Real Estate Ventures \| Two Real Estate Ventures \| Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments In real estate ventures \| investment	2
Acres \| a	1.4
Unconsolidated Real Estate Ventures \| One Real Estate Venture \| Land Under Active Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments In real estate ventures \| investment	1
Acres \| a	1.3
Unconsolidated Real Estate Ventures \| Two Other Real Estate Ventures \| Residential Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments In real estate ventures \| investment	1
Number of property units \| apartment	321
Parent Company \| Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments In real estate ventures \| investment	7