Restructuring (Details) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2018 USD ($) employee	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Restructuring Reserve [Roll Forward]
Provision	$ 5.7			$ 13.3			$ 44.4	$ 13.3
Drivetrain [Member]
Restructuring Reserve [Roll Forward]
Provision	0.5			0.7			6.0
Engine [Member]
Restructuring Reserve [Roll Forward]
Provision	5.2			12.6			38.1
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	26.5	$ 5.6	$ 5.4	2.3	$ 2.8	$ 6.4	5.4	6.4
Provision	1.4	27.1	1.8	1.4
Cash payments	(9.3)	(6.1)	(1.7)	(0.2)	(0.6)	(3.7)
Translation adjustment	(0.1)	(0.1)	0.1	0.1	0.1	0.1
Ending Balance	18.5	26.5	5.6	3.6	2.3	2.8	18.5	3.6
Employee Severance [Member] | Drivetrain [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	5.0	4.7	4.1	2.0	2.1	3.7	4.1	3.7
Provision	(0.5)	1.7	1.1	0.7
Cash payments	(3.5)	(1.3)	(0.6)	(0.2)	(0.2)	(1.6)
Translation adjustment	0.0	(0.1)	0.1	0.1	0.1	0.0
Ending Balance	1.0	5.0	4.7	2.6	2.0	2.1	1.0	2.6
Employee Severance [Member] | Engine [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	21.5	0.9	1.3	0.3	0.7	2.7	1.3	2.7
Provision	1.9	25.4	0.7	0.7
Cash payments	(5.8)	(4.8)	(1.1)	0.0	(0.4)	(2.1)
Translation adjustment	(0.1)	0.0	0.0	0.0	0.0	0.1
Ending Balance	$ 17.5	$ 21.5	$ 0.9	$ 1.0	$ 0.3	$ 0.7	17.5	$ 1.0
Emissions [Member] | Engine [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Expected Number of Positions Eliminated | employee	140
Emissions [Member] | Employee Severance [Member] | Engine [Member]
Restructuring Reserve [Roll Forward]
Provision							$ 26.9