EQUITY - Changes in common stock (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes in Common Stock [Roll Forward]
Beginning common shares outstanding	105,169,515	104,783,179
Grants under the Equity Plan	676,171	537,304
Common Unit redemptions	4,956	0
Performance share and other forfeitures	(210,897)	(166,478)
Shares retained for employee tax withholding requirements	(65,345)	(73,892)
Ending common shares outstanding	105,574,400	105,080,113