DEBT (Details)		6 Months Ended	12 Months Ended
		Jun. 30, 2023 USD ($) Integer	Dec. 31, 2022 USD ($) basisPoints
Secured and Unsecured Debt [Line Items]
Moody's Credit Rating		Baa2
Unsecured bank credit facilities, net of debt issuance costs		$ (2,002,000)	$ 168,454,000
Secured debt, net of debt issuance costs		1,974,000	2,031,000
Unsecured debt, net of debt issuance costs		1,726,024,000	1,691,259,000
Total debt		1,725,996,000	1,861,744,000
Secured and unsecured debt, net of debt issuance costs [Member]
Payments of principal over future years [Abstract]
2023 - Remainder of year		50,061,000
2024		170,122,000
2025		145,128,000
2026		141,672,000
2027		175,000,000
2028 and beyond		1,050,000,000
Total		$ 1,731,983,000
$100 million senior unsecured term loan (new in 2023)
Secured and Unsecured Debt [Line Items]
Debt Instrument, Term		7 years
Debt Instrument, Interest Rate, Effective Percentage		5.27%
Debt Instrument, Basis Spread on Variable Rate		1.35%
Unsecured debt, carrying amount		$ 100,000,000
$65 million unsecured term loan (repaid in 2023)
Secured and Unsecured Debt [Line Items]
Debt Instrument, Interest Rate, Effective Percentage		2.31%
Unsecured debt, carrying amount repaid		$ 65,000,000
Line of Credit [Member}
Secured and Unsecured Debt [Line Items]
Unsecured bank credit facilities - variable rate, carrying amount		0	170,000,000
Unsecured bank credit facilities, net of debt issuance costs		(2,002,000)	168,454,000
Unamortized debt issuance costs		(2,002,000)	(1,546,000)
Unsecured Debt [Member]
Secured and Unsecured Debt [Line Items]
Unamortized debt issuance costs		(3,976,000)	(3,741,000)
Unsecured debt, carrying amount	[1]	1,730,000,000	1,695,000,000
Unsecured debt, net of debt issuance costs		1,726,024,000	1,691,259,000
Secured Debt [Member]
Secured and Unsecured Debt [Line Items]
Secured debt-fixed rate, carrying amount	[1]	1,983,000	2,041,000
Secured debt, net of debt issuance costs		1,974,000	2,031,000
Unamortized debt issuance costs		(9,000)	(10,000)
Bank credit facilities amended effective in 2023 - $625 and $50 million
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Borrowing Capacity		$ 675,000,000
Bank credit facilities obtained in 2021 (former terms)
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Borrowing Capacity			$ 475,000,000
Debt instrument, basis spread above variable rate | basisPoints			77.5
Line of credit, facility fee (in basis points) | basisPoints			15
Debt Instrument, Maturity Date, Description			July 30, 2025
Nine bank group unsecured revolving credit facility [Member] | Bank credit facilities obtained in 2021 (former terms)
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Borrowing Capacity			$ 425,000,000
Pnc Na Unsecured revolving credit facility [Member] | Bank credit facilities obtained in 2021 (former terms)
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Borrowing Capacity			$ 50,000,000
Pnc Na Unsecured revolving credit facility [Member] | Bank credit facilities amended effective 2023 - $50 million
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Interest Rate at Period End		5.955%
Line of Credit Facility, Borrowing Capacity		$ 50,000,000
Debt instrument, basis spread above variable rate		76.5
Line of credit, facility fee (in basis points)		15
Debt Instrument, Maturity Date, Description		July 30, 2025
Extension option on credit facility		two six-month extensions
Unsecured bank credit facilities - variable rate, carrying amount		$ 0
Eleven bank group unsecured revolving credit facility | Bank credit facilities amended effective in 2023 - $625 and $50 million
Secured and Unsecured Debt [Line Items]
Sustainability performance linked basis point reduction (in basis points)		1
Initial pricing basis for credit facilities		BBB+/Baa1
Line of credit facility covenant terms, consolidated leverage ratio		32.50%
Eleven bank group unsecured revolving credit facility | Bank credit facilities amended effective 2023 - $625 million
Secured and Unsecured Debt [Line Items]
Line of Credit Facility, Interest Rate at Period End		6.006%
Line of Credit Facility, Borrowing Capacity		$ 625,000,000
Number of banks included in the unsecured revolving credit facility | Integer		11
Debt instrument, basis spread above variable rate		76.5
Line of credit, facility fee (in basis points)		15
Debt Instrument, Maturity Date, Description		July 30, 2025
Extension option on credit facility		two six-month extensions
Line of credit facility, accordion		$ 125,000,000
Unsecured bank credit facilities - variable rate, carrying amount		0
Payments of principal over future years [Abstract]
Line of Credit Facility, Increase (Decrease), Net		200,000,000
Letters of Credit Outstanding, Amount		$ 67,000

[1] These loans have a fixed interest rate or an effectively fixed interest rate due to interest rate swaps.