Pension and Other Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.5	$ 3.5
Interest cost	9.2	10.5
Expected return on plan assets	(8.5)	(11.0)
Amortization of prior service cost	0.0	0.0
Amortization of actuarial losses/(gains)	2.8	3.5
NET PERIODIC BENEFIT COST	5.0	6.5
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0
Interest cost	0.3	0.3
Expected return on plan assets	0.0	0.0
Amortization of prior service cost	(0.2)	(0.2)
Amortization of actuarial losses/(gains)	0.0	0.0
NET PERIODIC BENEFIT COST	$ 0.1	$ 0.1