EQUITY - Changes in common stock (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Beginning common shares outstanding	105,169,515	104,783,179
Common Unit redemptions	47,279	50,244
Performance share and other forfeitures	(212,643)	(167,757)
Shares retained for employee tax withholding requirements	(65,345)	(74,340)
Ending common shares outstanding	105,708,787	105,169,515
Grants under the Equity Plan
Class of Stock [Line Items]
Grants under the Equity Plan	676,171	537,734
Director stock
Class of Stock [Line Items]
Grants under the Equity Plan	93,810	40,455