Restructuring (Details) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2018 USD ($) employee	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Restructuring Reserve [Roll Forward]
Provision	$ 31.2		$ 0.0		$ 38.7	$ 0.0
Drivetrain [Member]
Restructuring Reserve [Roll Forward]
Provision	3.2				5.5
Engine [Member]
Restructuring Reserve [Roll Forward]
Provision	28.1				32.9
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	5.6	$ 5.4	2.8	$ 6.4	5.4	6.4
Provision	27.1	1.8
Cash payments	(6.1)	(1.7)	(0.6)	(3.7)
Translation adjustment	(0.1)	0.1	0.1	0.1
Ending Balance	26.5	5.6	2.3	2.8	26.5	2.3
Employee Severance [Member] | Drivetrain [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	4.7	4.1	2.1	3.7	4.1	3.7
Provision	1.7	1.1
Cash payments	(1.3)	(0.6)	(0.2)	(1.6)
Translation adjustment	(0.1)	0.1	0.1	0.0
Ending Balance	5.0	4.7	2.0	2.1	5.0	2.0
Employee Severance [Member] | Engine [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	0.9	1.3	0.7	2.7	1.3	2.7
Provision	25.4	0.7
Cash payments	(4.8)	(1.1)	(0.4)	(2.1)
Translation adjustment	0.0	0.0	0.0	0.1
Ending Balance	$ 21.5	$ 0.9	$ 0.3	$ 0.7	$ 21.5	$ 0.3
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	$ 25.3