SHARE-BASED COMPENSATION Total Stock Compensation Expense and Employee Stock Purchase Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Stock compensation expense	$ 4.9	$ 4.2	$ 3.5
Total unrecognized stock compensation expense	$ 10.3
Unrecognized compensation costs, recognition period	1 year 8 months 12 days
Employee Stock
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Stock compensation expense	$ 0.3	$ 0.2	$ 0.2
Number of shares authorized per employee	1,000
Discount rate	15.00%