Restructuring Restructuring (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) employee labor_union	Dec. 31, 2014 USD ($) employee	Dec. 31, 2013 USD ($)	Nov. 10, 2015	Feb. 28, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Agreements with Labor Unions, Number | labor_union									3
Asset Impairment Charges											$ 24.8
Restructuring expense	$ 24.4	$ 6.3	$ 10.5	$ 9.4	$ 17.8	$ 9.6	$ 13.0	$ 38.4	$ 65.7	$ 90.8	39.8
Drivetrain [Member]
Restructuring Cost and Reserve [Line Items]
Employee termination benefits, number of employees effected | employee									450
Employee termination benefits									$ 20.1	50.6	7.5
Other restructuring charges									7.9	11.2	0.6
Restructuring expense									$ 28.0	$ 61.8	32.9
Gustav Wahler GmbH u. Co. KG and General Partner [Member]
Restructuring Cost and Reserve [Line Items]
Employee termination benefits, number of employees effected | employee									70	95
Employee termination benefits									$ 11.6	$ 6.5
Corporate and Other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		$ 3.0	$ 9.4	$ 2.7	5.4	$ 3.5	$ 2.0	$ 1.1	12.5	12.0	4.0
Remy International Inc. [Member]
Restructuring Cost and Reserve [Line Items]
Employee termination benefits									10.1
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	29.4				43.9				29.4	43.9	11.3
Restructuring expense									43.9	56.8
Payments for Restructuring									(55.0)	(18.6)
Restructuring Reserve, Translation Adjustment									(3.8)	(5.6)
Remy International Inc. [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition, percentage of voting interests acquired												100.00%
Remy International Inc. [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense									0.4
Gustav Wahler GmbH u. Co. KG and General Partner [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition, percentage of voting interests acquired													100.00%
Engine [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	4.1				2.0				4.1	2.0	2.9
Restructuring expense									11.3	7.3
Payments for Restructuring									(9.0)	(7.9)
Restructuring Reserve, Translation Adjustment									(0.2)	(0.3)
Engine [Member] | Remy International Inc. [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense									0.0
Drivetrain [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 25.3				$ 41.9				25.3	41.9	$ 8.4
Restructuring expense									32.6	49.5
Payments for Restructuring									(46.0)	(10.7)
Restructuring Reserve, Translation Adjustment									(3.6)	$ (5.3)
Drivetrain [Member] | Remy International Inc. [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense									$ 0.4