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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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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, 2020 USD ($) a ft² investment apartment property	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of properties \| property	82
Investment in Real Estate Ventures, equity method	$ 389,811	$ 120,294
Accounts receivable	13,536	16,363
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable	1,200	800
Real Estate Venture \| Management Fees
Schedule of Equity Method Investments [Line Items]
Service and other revenue	4,700	4,300	$ 6,300
Real Estate Venture \| Leasing Commission Income
Schedule of Equity Method Investments [Line Items]
Service and other revenue	1,100	$ 1,700	$ 2,500
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment in Real Estate Ventures, equity method	389,800
Unconsolidated Real Estate Ventures \| Other Liabilities
Schedule of Equity Method Investments [Line Items]
Investment in Real Estate Ventures, equity method	$ (11,500)
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 \| Office Properties
Schedule of Equity Method Investments [Line Items]
Number of properties \| investment	5
Rentable square feet \| ft²	8.4
Unconsolidated Real Estate Ventures \| Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of properties \| property	9
Number of real estate properties with negative investment balances \| property	1
Unconsolidated Real Estate Ventures \| Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of properties \| investment	2
Acres \| a	1.4
Unconsolidated Real Estate Ventures \| Land Under Active Development
Schedule of Equity Method Investments [Line Items]
Number of properties \| investment	1
Acres \| a	1.3
Unconsolidated Real Estate Ventures \| Residential Tower
Schedule of Equity Method Investments [Line Items]
Number of properties \| investment	1
Number of property units \| apartment	321