SEGMENT INFORMATION - Schedule of Unconsolidated Real Estate Ventures of Company's Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Investment in real estate ventures	$ 570,370		$ 570,455
Equity in income (loss) of real estate ventures	(10,511)	$ (13,588)
Philadelphia CBD
Segment Reporting Information [Line Items]
Investment in real estate ventures	458,335		452,334
Equity in income (loss) of real estate ventures	(4,208)	(9,613)
Mid-Atlantic Office JV
Segment Reporting Information [Line Items]
Investment in real estate ventures	10,684		10,844
Equity in income (loss) of real estate ventures	(161)	0
MAP Venture
Segment Reporting Information [Line Items]
Investment in real estate ventures	0		0
Equity in income (loss) of real estate ventures	0	(3,223)
Austin, Texas
Segment Reporting Information [Line Items]
Investment in real estate ventures	84,500		90,495
Equity in income (loss) of real estate ventures	(5,888)	0
Other
Segment Reporting Information [Line Items]
Investment in real estate ventures	16,851		$ 16,782
Equity in income (loss) of real estate ventures	$ (254)	$ (752)