Pension Plans and Other Benefits - Changes in Defined Benefit Obligations and Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure
Defined Benefit Plan Benefit Obligation Decrease Lump Sum	$ 43.3
Change in plan assets:
Fair value at beginning of period	715.6
Fair value at end of period	793.2	$ 715.6
Amounts recognized in the consolidated balance sheets:
Noncurrent liabilities	(53.7)	(64.9)
North American Pension Plans
Change in projected benefit obligation:
Benefit obligation at beginning of period	713.5	731.2
Service cost	5.9	5.8	$ 6.5
Interest cost	24.3	25.1	30.1
Actuarial loss	44.2	16.0
Currency fluctuations	24.0	9.7
Benefits paid	(45.8)	(84.9)
Plan Amendments	0.0	10.6
Projected benefit obligation at end of period	766.1	713.5	731.2
Change in plan assets:
Fair value at beginning of period	715.6	726.7
Currency fluctuations	25.9	10.1
Actual return	85.8	52.2
Company contribution	11.7	11.5
Benefits paid	(45.8)	(84.9)
Fair value at end of period	793.2	715.6	$ 726.7
Funded status of the plans as of the end of period	27.1	2.1
Amounts recognized in the consolidated balance sheets:
Noncurrent assets	41.1	24.8
Current liabilities	(0.8)	(0.7)
Noncurrent liabilities	(13.2)	(22.0)
Amounts recognized in accumulated other comprehensive (income) loss
Prior service costs	20.8	23.2
Actuarial loss	109.8	109.6
Accumulated benefit obligation for the defined benefit pension plans	765.1	712.1
North American Postretirement Benefit Plans
Change in projected benefit obligation:
Benefit obligation at beginning of period	44.9
Projected benefit obligation at end of period	$ 41.3	$ 44.9