Defined Benefit Pension Plans and Other Post-Employment Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Components of net periodic benefit (income) cost:
Service cost	$ 1.0	$ 1.7
Interest cost	5.5	5.8
Expected return on plan assets	(9.6)	(10.1)
Amortization of net actuarial loss	0.9	1.6
Net periodic benefit income	(2.2)	(1.0)
Cost of settlement/curtailment	0.0	0.5
Total benefit (income) cost	(2.2)	(0.5)
U.S.
Components of net periodic benefit (income) cost:
Service cost	0.0	0.0
Interest cost	1.6	1.8
Expected return on plan assets	(2.2)	(2.5)
Amortization of net actuarial loss	0.3	0.2
Net periodic benefit income	(0.3)	(0.5)
Cost of settlement/curtailment	0.0	0.0
Total benefit (income) cost	(0.3)	(0.5)
International
Components of net periodic benefit (income) cost:
Service cost	1.0	1.7
Interest cost	3.9	4.0
Expected return on plan assets	(7.4)	(7.6)
Amortization of net actuarial loss	0.6	1.4
Net periodic benefit income	(1.9)	(0.5)
Cost of settlement/curtailment	0.0	0.5
Total benefit (income) cost	(1.9)	0.0
Other employee benefit plans
Components of net periodic benefit (income) cost:
Interest cost	0.3	0.5
Amortization of net prior service cost	(0.1)	(0.5)
Net periodic benefit income	$ 0.2	$ 0.0