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Area of land held.

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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 17, 2022 USD ($) ft²	Jun. 30, 2022 USD ($) a ft² property apartment	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) a ft² property apartment	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property		78		78
Investment in unconsolidated real estate ventures		$ 458,840		$ 458,840		$ 435,506
Accounts receivable		$ 13,584		$ 13,584		11,875
Rentable area (in square feet) \| ft²		13,639,287		13,639,287
Purchase price				$ 3,446	$ 0
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable		$ 2,800		2,800		$ 2,500
Management Fees \| Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue		2,100	$ 2,100	4,000	4,100
Leasing Commission Income \| Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue		800	$ 600	1,100	$ 1,900
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated real estate ventures		$ 429,300		$ 429,300
Unconsolidated Real Estate Ventures \| Minimum
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		15.00%		15.00%
Unconsolidated Real Estate Ventures \| Maximum
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		70.00%		70.00%
Unconsolidated Real Estate Ventures \| Office properties
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| property		5		5
Rentable area (in square feet) \| ft²		9,100,000		9,100,000
Unconsolidated Real Estate Ventures \| Other Liabilities
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated real estate ventures		$ 29,600		$ 29,600
Unconsolidated Real Estate Ventures \| Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property		10		10
Number of properties with negative investment balances \| property		1		1
Unconsolidated Real Estate Ventures \| Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| property		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 \| property		1		1
Area of land (in acres) \| a		1.0		1.0
Unconsolidated Real Estate Ventures \| Mixed Use Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| property		1		1
Rentable area (in square feet) \| ft²		200,000		200,000
Number of apartment units (in units) \| apartment		250		250
Unconsolidated Real Estate Ventures \| Residential Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures \| property		1		1
Number of apartment units (in units) \| apartment		321		321
Cira Square REIT, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	20.00%
Gross purchase price	$ 383,000
Purchase price	$ 28,600
Cira Square REIT, LLC \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Spread on variable rate	3.50%
Cira Square REIT, LLC \| Secured Debt
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount	$ 257,700
Cira Square REIT, LLC \| Office properties
Schedule of Equity Method Investments [Line Items]
Rentable area (in square feet) \| ft²	862,692