Goodwill and Other Intangibles - Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Changes in the carrying amount of goodwill
Net goodwill balance, January 1	$ 1,197.0
Ending balance, December 31	1,205.7
Goodwill impairment test, weighted average cost of capital discount rate for future cash flow	10.00%
Sensitivity analysis Increase in discount rate	1.00%
Sensitivity analysis decrease in operating margin assumption	1.00%
Engine [Member]
Changes in the carrying amount of goodwill
Gross goodwill balance, January 1	1,331.9		1,324.1
Accumulated impairment losses, January 1			(501.8)	(501.8)
Net goodwill balance, January 1	830.1		822.3
Acquisition	76.9	[1]		0
Divestitures			(4.6)
Translation adjustment and other	(46.8)		12.4
Ending balance, December 31	860.2		830.1	822.3
Drivetrain [Member]
Changes in the carrying amount of goodwill
Gross goodwill balance, January 1	367.1		359.3
Accumulated impairment losses, January 1			(0.2)	(0.2)
Net goodwill balance, January 1	366.9		359.1
Acquisition	0			0
Translation adjustment and other	(21.4)		7.8
Ending balance, December 31	$ 345.5		$ 366.9	$ 359.1

[1] *Goodwill acquired relates to the Company's 2014 purchase of Gustav Wahler GmbH u. Co. KG and its general partner.