STOCK REPURCHASE PROGRAM (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 20, 2016
STOCK REPURCHASE PROGRAM
Share repurchases authorized amount				$ 350,000
Aggregate amount of share repurchases (in dollars)	$ 120,540
Common stock repurchased (retired and held in treasury) (in shares)	1,900
Common stock repurchased (retired and held in treasury)	$ 161,500
Common stock repurchased and retired (in shares)	512	1,700
Common stock repurchased and retired	$ 40,994	$ 131,371	$ 13,887
Remaining authorized repurchase amount	$ 141,900