COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands		1 Months Ended	12 Months Ended
	Oct. 21, 2020 USD ($)	Feb. 28, 2021 property	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2004 ft²
Property Subject to or Available for Operating Lease [Line Items]
Unconsolidated Real Estate Venture Debt at 100%, gross			$ 1,204,779		$ 1,412,758
Preferred Equity Investment Obligation
Property Subject to or Available for Operating Lease [Line Items]
Other commitments					15,000
Commerce Square | Preferred Equity Investment Obligation
Property Subject to or Available for Operating Lease [Line Items]
Other commitments					20,000
Amount committed to date					9,500
Drexel Square
Property Subject to or Available for Operating Lease [Line Items]
Other commitments					6,200
Estimated potential additional contribution obligation					2,200
Natural Disasters and Other Casualty Events
Property Subject to or Available for Operating Lease [Line Items]
Number of properties damaged | property		1
Write-off of fixed assets				$ 1,200
Restoration liability			800	7,200
Business interruption costs				3,900
Insurance proceeds			$ 2,800	15,300
Natural Disasters and Other Casualty Events | Other Income
Property Subject to or Available for Operating Lease [Line Items]
Insurance proceeds				3,000
Natural Disasters and Other Casualty Events | Accounts Payable and Accrued Liabilities
Property Subject to or Available for Operating Lease [Line Items]
Restoration liability				$ 1,900
Unconsolidated Real Estate Ventures
Property Subject to or Available for Operating Lease [Line Items]
Unconsolidated Real Estate Venture Debt at 100%, gross					1,412,800
Two Logan Square
Property Subject to or Available for Operating Lease [Line Items]
Rentable area (in square feet) | ft²						708,844
Settlement liabilities					$ 600
Two Logan Square | Secured fix rate debt
Property Subject to or Available for Operating Lease [Line Items]
Repayments of long-term debt	$ 79,800