STOCK-BASED COMPENSATION AND EMPLOYEE BENEFIT PLANS (Employee Benefit Plans) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) employee	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Number of active non-supervisory Canadian employees | employee	14
Net periodic benefit cost	$ 0.4	$ 0.3	$ 0.3
Pension assets measured at fair value	8.4	8.4
Projected benefit obligation	9.9	10.0
Fair Value, Inputs, Level 1
Defined Contribution Plan Disclosure [Line Items]
Pension assets measured at fair value	3.5	6.6
Fair Value, Inputs, Level 2
Defined Contribution Plan Disclosure [Line Items]
Pension assets measured at fair value	$ 4.9	$ 1.8