REAL ESTATE INVESTMENTS - Schedule of Properties Classified as Held for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Real estate investments:
Accumulated depreciation	$ (1,125,145)	$ (1,063,060)
Operating real estate investments, net	3,597,211	3,617,240
Total real estate investments, net	2,836,344	2,904,788
Deferred costs, net	95,102	96,639
Intangible assets, net	11,676	18,451
Other assets	90,362	78,667
Total assets	3,954,485	3,874,505
LIABILITIES HELD FOR SALE
Mortgage notes payable, net	241,383	0
Deferred income, gains and rent	24,786	25,082
Intangible liabilities, net	8,811	10,322
Total liabilities	2,397,825	$ 2,241,171
Held-for-sale | Pennsylvania suburbs segment
Real estate investments:
Total real estate investments, net	49,683
Deferred costs, net	339
Intangible assets, net	1,755
Accrued Rent Receivable	790
Other assets	97
Total assets	52,664
LIABILITIES HELD FOR SALE
Mortgage notes payable, net
Deferred income, gains and rent	383
Intangible liabilities, net	658
Total liabilities	1,041
Held-for-sale | Pennsylvania suburbs segment | Real Estate Excluding Construction In Progress
Real estate investments:
Operating properties	54,701
Accumulated depreciation	(5,388)
Operating real estate investments, net	49,313
Held-for-sale | Pennsylvania suburbs segment | Construction in Progress
Real estate investments:
Operating real estate investments, net	$ 370