Retirement Benefit Plans - Benefit Obligation and Plan Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Amounts recognized in Balance Sheet [Abstract]
Non-current liabilities	$ 509.7		$ 457.0
NSK Warner [Member]
Amounts recognized in accumulated other comprehensive Income Loss) [Abstract]
Net amount recognized	7.9	[1]	6.9	[1]
U.S. Plans:
Change in benefit obligation [Roll Forward]
Projected benefit obligation, January 1	337.4		326.2
Service cost	0		0		0
Interest cost	14.3		16.1		17.5
Plan participants’ contributions	0		0
Plan amendments	0		0
Actuarial (gain) loss	15.5		21.8
Currency translation	0		0
Other	0		0
Benefits paid	(37.1)		(26.7)
Projected benefit obligation, December 31	330.1		337.4		326.2
Change in plan assets:
Fair value of plan assets, January 1	290.4		287.2
Actual return on plan assets	29.4		8.9
Employer contribution	0		21.0
Currency translation	0		0
Other	0		0
Fair value of plan assets, December 31	282.7		290.4		287.2
Funded status of plan	(47.4)		(47.0)
Amounts recognized in Balance Sheet [Abstract]
Non-current assets	0		0
Current liabilities	0.1		0.1
Non-current liabilities	47.3		46.9
Net amount recognized	(47.4)		(47.0)
Amounts recognized in accumulated other comprehensive Income Loss) [Abstract]
Net actuarial loss	(163.8)		(172.8)
Net prior service cost (credit)	(10.5)		(11.3)
Net amount recognized	153.3	[1]	161.5	[1]
Defined Benefit Plan, Accumulated Benefit Obligation	330.1		337.4
Non-U.S. Plans:
Change in benefit obligation [Roll Forward]
Projected benefit obligation, January 1	344.3		326.0
Service cost	9.1		9.1		7.4
Interest cost	17.2		17.8		17.6
Plan participants’ contributions	0.5		0.3
Plan amendments	0		(0.5)
Actuarial (gain) loss	84.1		11.9
Currency translation	11.3		(5.8)
Other	(4.5)		0.9
Benefits paid	(14.4)		(15.4)
Projected benefit obligation, December 31	447.6		344.3		326.0
Change in plan assets:
Fair value of plan assets, January 1	154.9		154.6
Actual return on plan assets	15.0		5.0
Employer contribution	18.0		16.0
Currency translation	6.0		(0.7)
Other	(2.1)		(4.9)
Fair value of plan assets, December 31	177.9		154.9		154.6
Funded status of plan	(269.7)		(189.4)
Amounts recognized in Balance Sheet [Abstract]
Non-current assets	0		0.5
Current liabilities	7.0		6.5
Non-current liabilities	262.7		183.4
Net amount recognized	(269.7)		(189.4)
Amounts recognized in accumulated other comprehensive Income Loss) [Abstract]
Net actuarial loss	(135.1)		(54.4)
Net prior service cost (credit)	0.5		0.8
Net amount recognized	135.6	[1]	55.2	[1]
Defined Benefit Plan, Accumulated Benefit Obligation	430.2		327.9
U.S. other postretirement benefit plans [Member]
Change in benefit obligation [Roll Forward]
Projected benefit obligation, January 1	251.0		261.9
Service cost	0.5		0.7		0.8
Interest cost	10.1		11.8		14.5
Plan participants’ contributions	0		0
Plan amendments	(0.3)		3.9
Actuarial (gain) loss	(20.7)		(6.8)
Currency translation	0		0
Other	0		0
Benefits paid	(20.1)		(20.5)
Projected benefit obligation, December 31	220.5		251.0		261.9
Change in plan assets:
Funded status of plan	(220.5)		(251.0)
Amounts recognized in Balance Sheet [Abstract]
Non-current assets	0		0
Current liabilities	20.8		24.3
Non-current liabilities	199.7		226.7
Net amount recognized	(220.5)		(251.0)
Amounts recognized in accumulated other comprehensive Income Loss) [Abstract]
Net actuarial loss	(78.7)		(106.3)
Net prior service cost (credit)	(42.6)		(48.7)
Net amount recognized	$ 36.1	[1]	$ 57.6	[1]

[1] AOCI shown above does not include our equity investee, NSK-Warner. NSK-Warner had an AOCI loss of $7.9 million and $6.9 million at December 31, 2012 and 2011, respectively.