Defined Benefit Pension Plans and Other Post-Employment Benefit Plans - Net Period Benefit Costs Charged to Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Total income included in discontinued operations	$ (2.1)	$ (0.1)	$ (4.3)	$ (0.6)
Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Total income included in discontinued operations		(0.2)		(0.4)
Defined benefit pension plans | Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Total income included in discontinued operations		(0.2)		(0.4)
Other employee benefit plans | Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Total income included in discontinued operations		$ 0.0		$ 0.0