EARNINGS PER SHARE - Schedule of Earnings per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income (Numerator)
Net income	$ 43,383	$ 29,309	$ 66,154	$ 73,304
Net income attributable to noncontrolling interests	(1,086)	(1,268)	(2,185)	(2,139)
Numerator for basic and diluted earnings per common share available to common shareholders	$ 42,297	$ 28,041	$ 63,969	$ 71,165
Shares (Denominator)
Weighted average common shares outstanding (shares)	91,764	102,224	92,032	102,062
Dilutive effect of stock-settled appreciation rights and outstanding stock options (shares)	1,399	762	1,157	890
Weighted average common and common equivalent shares outstanding (shares)	93,163	102,986	93,189	102,952