EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Retirement Benefits [Abstract]
Expected employer contribution	$ 21.0		$ 21.0
Increase from prior year employer contributions	14.9		14.9
Components of net pension expense
Service cost	1.0	$ 1.3	2.0	$ 2.5
Interest cost	2.1	2.8	4.1	5.6
Expected return on plan assets	(2.9)	(3.3)	(5.8)	(6.7)
Recognized net actuarial loss	0.7	1.1	1.4	2.3
Net pension expense	$ 0.9	$ 1.9	$ 1.7	$ 3.7