Pensions and Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pensions
Components of net annual benefit cost (income):
Service cost	$ 0.9	$ 1.1
Interest cost	9.1	12.2
Expected return on plan assets	(9.3)	(13.4)
Amortization of prior service cost (credit)	0.1	0.1
Recognized net actuarial and other (gain) loss	2.5	4.6
Net periodic benefit cost (income)	3.3	4.6
Other Benefits
Components of net annual benefit cost (income):
Service cost	0.0	0.0
Interest cost	0.1	0.2
Expected return on plan assets	0.0	0.0
Amortization of prior service cost (credit)	0.0	0.0
Recognized net actuarial and other (gain) loss	(0.2)	(0.2)
Net periodic benefit cost (income)	$ (0.1)	$ 0.0