Restructuring (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended							6 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 labor_union	Jun. 30, 2013	Jun. 30, 2014 Employee Severance [Member]	Mar. 31, 2014 Employee Severance [Member]	Jun. 30, 2014 Employee Severance [Member] Drivetrain [Member]	Mar. 31, 2014 Employee Severance [Member] Drivetrain [Member]	Jun. 30, 2014 Employee Severance [Member] Engine [Member]	Mar. 31, 2014 Employee Severance [Member] Engine [Member]	Jun. 30, 2014 Wahler	Jun. 30, 2014 Wahler employee	Jun. 30, 2014 Drivetrain [Member]	Jun. 30, 2014 Drivetrain [Member] employee	Jun. 30, 2014 Drivetrain [Member] Employee Severance [Member]	Feb. 28, 2014 Wahler
Restructuring Cost and Reserve [Line Items]
Finalization of severance agreements, number of labor unions			2
Employee termination costs, number of employees												60		350
Employee termination benefits											$ 3.1		$ 6.4	$ 38.5
Other expense													3.0	6.3
Expected employee termination benefit costs to be incurred	20.0		20.0
Equity interest acquired																100.00%
Expected employee termination benefit costs to be incurred, period of recognition															2 years
Restructuring Reserve [Roll Forward]
Balance at December 31, 2013					41.2	11.2	39.3	8.4	1.9	2.8
Provision	15.0	0	54.5	0	10.0	32.8	6.4	32.1	3.6	0.7			9.4	44.8
Cash payments					(6.6)	(2.8)	(2.7)	(1.2)	(3.9)	(1.6)
Translation adjustment					(0.2)	0	(0.2)	0	0	0
Balance at March 31, 2014					$ 44.4	$ 41.2	$ 42.8	$ 39.3	$ 1.6	$ 1.9