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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) |  |  |  | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 29, 2022 USD ($) numberOfLoan | Jun. 30, 2022 | Mar. 17, 2022 USD ($) ft² | Sep. 30, 2022 USD ($) a ft² property apartment | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) a ft² property apartment | Sep. 30, 2021 USD ($) | Jul. 14, 2022 USD ($) ft² | Dec. 31, 2021 USD ($) | Dec. 01, 2021 USD ($) ft² apartment property
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Number of real estate properties | property |  |  |  | 78 |  | 78 |  |  |  |
Investment in unconsolidated real estate ventures |  |  |  | $ 579,457,000 |  | $ 579,457,000 |  |  | $ 435,506,000 |
Accounts receivable |  |  |  | 11,398,000 |  | 11,398,000 |  |  | 11,875,000 |
Investment in real estate ventures |  |  |  | $ 546,935,000 |  | $ 546,935,000 |  |  | 411,110,000 |
Rentable area (in square feet) | ft² |  |  |  | 13,664,209 |  | 13,664,209 |  |  |  |
Principal balance outstanding |  |  |  | $ 2,074,610,000 |  | $ 2,074,610,000 |  |  |  |
Purchase price |  |  |  |  |  | 3,446,000 | $ 0 |  |  |
Unsecured Debt |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Principal balance outstanding |  |  |  | 2,074,610,000 |  | 2,074,610,000 |  |  | 1,851,610,000 |
Unsecured Debt | $600 million Unsecured Credit Facility |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Principal balance outstanding |  |  |  | 246,000,000 |  | 246,000,000 |  |  | 23,000,000 |
Debt instrument, face amount |  |  |  | 600,000,000 |  | $ 600,000,000 |  |  |  |
Unsecured Debt | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | $600 million Unsecured Credit Facility |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  |  | 1.15% |  |  |  |
Unsecured Debt | Daily SOFR Adjustment | $600 million Unsecured Credit Facility |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  | 0.10% |  |  |  | 0.10% |  |  |  |
Real Estate Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Accounts receivable |  |  |  | 2,900,000 |  | $ 2,900,000 |  |  | $ 2,500,000 |
Management Fees | Real Estate Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Service and other revenue |  |  |  | 2,200,000 | $ 2,100,000 | 6,200,000 | 6,200,000 |  |  |
Leasing Commission Income | Real Estate Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Service and other revenue |  |  |  | 700,000 | $ 700,000 | 1,700,000 | $ 2,600,000 |  |  |
3151 Market Street |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Investment in real estate ventures |  |  |  |  |  |  |  | $ 308,000,000 |  |
Rentable area (in square feet) | ft² |  |  |  |  |  |  |  | 417,000 |  |
3151 Market Street | Joint Venture With Unaffiliated Third Party |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Investment in real estate ventures |  |  |  |  |  |  |  | $ 55,000,000 |  |
Unconsolidated Real Estate Ventures |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Investment in unconsolidated real estate ventures |  |  |  | $ 546,900,000 |  | $ 546,900,000 |  |  |  |
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 |  |  |  | $ 32,500,000 |  | $ 32,500,000 |  |  |  |
Unconsolidated Real Estate Ventures | Unconsolidated Properties |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Number of real estate properties | property |  |  |  | 13 |  | 13 |  |  |  |
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 |  |  |  | 4 |  | 4 |  |  |  |
Area of land (in acres) | a |  |  |  | 7.5 |  | 7.5 |  |  |  |
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 |  |  |  |
One Uptown Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Investment in real estate ventures |  |  |  |  |  |  |  |  |  | $ 328,400,000
Number of apartment residence | apartment |  |  |  |  |  |  |  |  |  | 341
Joint venture, funding committed by other party |  |  |  |  |  |  |  |  |  | $ 64,500,000
One Uptown Venture | Carry Guarantee | Loans Payable |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Guarantee percent | 30.00% |  |  |  |  |  |  |  |  |
One Uptown Venture | Limited Payment Guarantee | Loans Payable |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Guarantee percent | 15.00% |  |  |  |  |  |  |  |  |
One Uptown Venture | Preferred Stock |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  |  |  |  |  |  | 50.00%
One Uptown Venture | Common Stock |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  |  |  |  |  |  | 50.00%
One Uptown Venture | Canyon Partners Real Estate |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Number of joint ventures | property |  |  |  |  |  |  |  |  |  | 2
One Uptown Venture | Construction Loans |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Number of loans closed | numberOfLoan | 2 |  |  |  |  |  |  |  |  |
Principal balance outstanding | $ 121,700,000 |  |  |  |  |  |  |  |  |
One Uptown Venture | Construction Loans | Multifamily Joint Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Principal balance outstanding | $ 85,000,000 |  |  |  |  |  |  |  |  |
One Uptown Venture | Construction Loans | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Spread on variable rate | 3.00% |  |  |  |  |  |  |  |  |
One Uptown Venture | Construction Loans | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Multifamily Joint Venture |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Spread on variable rate | 2.45% |  |  |  |  |  |  |  |  |
One Uptown Venture | Class A Workspace |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Rentable area (in square feet) | ft² |  |  |  |  |  |  |  |  |  | 348,000
One Uptown Venture | Street Level Retail |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Rentable area (in square feet) | ft² |  |  |  |  |  |  |  |  |  | 15,000
Joint Venture With Unaffiliated Third Party | 3151 Market Street | Joint Venture With Unaffiliated Third Party |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  |  |  |  | 45.00% |  |
Cira Square REIT, LLC |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  | 20.00% |  |  |  |  |  |  |
Gross purchase price |  |  | $ 383,000,000 |  |  |  |  |  |  |
Purchase price |  |  | $ 28,600,000 |  |  |  |  |  |  |
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 |  |  | $ 257,700,000 |  |  |  |  |  |  |
Cira Square REIT, LLC | Office properties |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |
Rentable area (in square feet) | ft² |  |  | 862,692 |  |  |  |  |  |  |

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