EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings per share — Basic:
Earnings from continuing operations	$ 89,511	$ 59,040	$ 166,962	$ 148,971
Less: Earnings allocated to unvested stock	(326)	(223)	(601)	(538)
Earnings from continuing operations available to common shareholders — Basic	$ 89,185	$ 58,817	$ 166,361	$ 148,433
Weighted average common shares outstanding - Basic (in shares)	52,397	52,405	52,391	52,671
Earnings from continuing operations per common share - Basic (in dollars per share)	$ 1.70	$ 1.12	$ 3.18	$ 2.82
Earnings per share — Diluted:
Earnings from continuing operations	$ 89,511	$ 59,040	$ 166,962	$ 148,971
Less: Earnings allocated to unvested stock	(326)	(223)	(601)	(538)
Earnings from continuing operations available to common shareholders — Diluted	$ 89,185	$ 58,817	$ 166,361	$ 148,433
Weighted average common shares outstanding - Basic (in shares)	52,397	52,405	52,391	52,671
Effect of dilutive equity awards (in shares)	373	371	349	356
Weighted average common shares outstanding — Diluted (in shares)	52,770	52,776	52,740	53,027
Earnings from continuing operations per common share - Diluted (in dollars per share)	$ 1.69	$ 1.12	$ 3.15	$ 2.80
Anti-dilutive equity awards not included above (in shares)	1,197	843	1,230	889