Restructuring (Details) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2015 USD ($) employee labor_union	Jun. 30, 2014 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Finalization of severance agreements, number of labor unions | labor_union					2
Restructuring Reserve [Roll Forward]
Provision	$ 19.9		$ 15.0		$ 32.0	$ 54.5
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	35.2	$ 43.9	41.2	$ 11.3	43.9	11.3
Provision	9.4	7.8	10.0	32.8
Cash payments	(27.6)	(11.6)	(6.6)	(2.9)
Translation adjustment	1.3	(4.9)	(0.2)
Ending Balance	18.3	35.2	44.4	41.2	18.3	44.4
Employee Severance [Member] | Drivetrain [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	33.9	41.9	39.3	8.4	41.9	8.4
Provision	6.8	7.4	6.4	32.1
Cash payments	(25.9)	(10.7)	(2.7)	(1.2)
Translation adjustment	1.3	(4.7)	(0.2)
Ending Balance	16.1	33.9	42.8	39.3	16.1	42.8
Employee Severance [Member] | Engine [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	1.3	2.0	1.9	2.9	2.0	2.9
Provision	2.6	0.4	3.6	0.7
Cash payments	(1.7)	(0.9)	(3.9)	(1.7)
Translation adjustment	0.0	(0.2)	0.0
Ending Balance	2.2	$ 1.3	1.6	$ 1.9	2.2	1.6
Corporate and Other [Member]
Restructuring Reserve [Roll Forward]
Provision	9.4		2.0		$ 12.1	$ 3.1
Gustav Wahler GmbH u. Co. KG and its general partner
Restructuring Cost and Reserve [Line Items]
Employee termination costs, number of employees | employee						60
Employee termination benefits						$ 3.1
Drivetrain [Member]
Restructuring Cost and Reserve [Line Items]
Employee termination costs, number of employees | employee					350
Employee termination benefits	6.8		6.4		$ 13.2	38.5
Other expense	1.1		3.0		2.0	6.3
Restructuring Reserve [Roll Forward]
Provision	$ 7.9		$ 9.4		$ 15.2	$ 44.8