SEGMENT INFORMATION - Schedule of Net Operating Income of Company's Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Total revenue	$ 121,417	$ 131,782	$ 363,504	$ 383,612
Operating expenses	(45,409)	(46,279)	(138,356)	(140,007)
Net operating income	76,008	85,503	225,148	243,605
Operating Segments | Philadelphia CBD
Segment Reporting Information [Line Items]
Total revenue	58,250	56,448	170,321	169,159
Operating expenses	(21,975)	(19,959)	(62,978)	(58,912)
Net operating income	36,275	36,489	107,343	110,247
Operating Segments | Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Total revenue	31,563	31,681	94,804	95,366
Operating expenses	(9,518)	(10,081)	(29,536)	(29,337)
Net operating income	22,045	21,600	65,268	66,029
Operating Segments | Austin, Texas
Segment Reporting Information [Line Items]
Total revenue	16,837	21,951	53,487	67,360
Operating expenses	(6,542)	(8,429)	(22,094)	(26,276)
Net operating income	10,295	13,522	31,393	41,084
Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	10,091	10,430	30,609	31,706
Operating expenses	(4,257)	(5,076)	(13,861)	(15,670)
Net operating income	5,834	5,354	16,748	16,036
Corporate
Segment Reporting Information [Line Items]
Total revenue	4,676	11,272	14,283	20,021
Operating expenses	(3,117)	(2,734)	(9,887)	(9,812)
Net operating income	$ 1,559	$ 8,538	$ 4,396	$ 10,209