PENSION AND POST-RETIREMENT PLANS (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Pension Benefits
Components of Net Periodic (Benefit) Cost
Service cost	$ 2.6	$ 2.5
Interest cost	7.1	7.1
Expected return on plan assets	(10.4)	(10.5)
Amortization of net gain	4.8	2.3
Amortization of prior service cost	(1.7)	(1.7)
Net periodic cost (benefit)	2.4	(0.3)
Employer contribution	4.7
Full year expected cash contributions to pension plan	6.2
Post-retirement Benefits
Components of Net Periodic (Benefit) Cost
Service cost	1.2	0.8
Interest cost	1.9	1.9
Amortization of net gain	1.8	0.4
Net periodic cost (benefit)	$ 4.9	$ 3.1