Pension and Other Postretirement Benefits - Components of Defined Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets
Company contributions	$ 13.4	$ 37.5
Settlements			$ (35.7)
Amount recognized in the consolidated balance sheets:
Pension asset	44.2	42.8
Decrease in defined benefit obligation	(13.0)	4.0
UNITED STATES
Change in plan assets
Settlements			(3.2)
Pensions
Change in projected benefit obligation
Projected benefit obligation at January 1	1,261.3	1,385.8
Service cost	4.2	6.3	7.4
Interest cost	47.6	44.5	44.3
Actuarial loss (gain)	153.0	(89.9)
Amendments	0.0	0.0
Foreign currency exchange rate changes and other	0.0	(0.4)
Plan participants’ contributions	0.0	0.0
Special termination benefits	0.0	3.9
Settlements	(3.5)	(4.4)
Curtailments	0.0	(0.9)
Benefits paid	(83.5)	(83.6)
Projected benefit obligation at December 31	1,379.1	1,261.3	1,385.8
Change in plan assets
Fair value of plan assets at January 1	1,269.7	1,339.9
Actual return on plan assets	196.2	(18.0)
Foreign currency exchange rate changes	(0.2)	(0.2)
Company contributions	11.9	36.0
Plan participants’ contributions	0.0	0.0
Settlements	(3.5)	(4.4)
Benefits paid	(83.5)	(83.6)
Fair value of plan assets at December 31	1,390.6	1,269.7	1,339.9
Funded Status
Net funded status of the plan (liability)	11.5	8.4
Amount recognized in the consolidated balance sheets:
Pension asset	44.2	42.8
Accrued benefit liability	(32.7)	(34.4)
Total	11.5	8.4
Other Benefits
Change in projected benefit obligation
Projected benefit obligation at January 1	18.9	19.0
Service cost	0.0	0.0	0.0
Interest cost	0.6	0.7	0.7
Actuarial loss (gain)	(2.2)	0.6
Amendments	0.0	(0.1)
Foreign currency exchange rate changes and other	0.0	0.0
Plan participants’ contributions	0.4	0.7
Special termination benefits	0.0	0.0
Settlements	0.0	0.0
Curtailments	0.0	0.2
Benefits paid	(1.9)	(2.2)
Projected benefit obligation at December 31	15.8	18.9	19.0
Change in plan assets
Fair value of plan assets at January 1	0.0	0.0
Actual return on plan assets	0.0	0.0
Foreign currency exchange rate changes	0.0	0.0
Company contributions	1.5	1.5
Plan participants’ contributions	0.4	0.7
Settlements	0.0	0.0
Benefits paid	(1.9)	(2.2)
Fair value of plan assets at December 31	0.0	0.0	$ 0.0
Funded Status
Net funded status of the plan (liability)	(15.8)	(18.9)
Amount recognized in the consolidated balance sheets:
Pension asset	0.0	0.0
Accrued benefit liability	(15.8)	(18.9)
Total	(15.8)	(18.9)
Pension Plan, With Assets | UNITED STATES
Funded Status
Net funded status of the plan (liability)	44.2	42.8
Pension Plan, With Assets | Non-U.S.
Funded Status
Net funded status of the plan (liability)	(1.3)	(1.9)
Other Benefits, With Assets | UNITED STATES
Funded Status
Net funded status of the plan (liability)	0.0	0.0
Other Benefits, With Assets | Non-U.S.
Funded Status
Net funded status of the plan (liability)	0.0	0.0
Pension Plan, Without Assets | UNITED STATES
Funded Status
Net funded status of the plan (liability)	(22.4)	(24.6)
Other Benefits, Without Assets | UNITED STATES
Funded Status
Net funded status of the plan (liability)	(15.8)	(18.9)
Pensions
Funded Status
Net funded status of the plan (liability)	(9.0)	(7.9)
Other Benefit Plans
Funded Status
Net funded status of the plan (liability)	$ 0.0	$ 0.0