Retirement and Other Postretirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		12 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2011	Jun. 30, 2011	Jun. 30, 2012 U.S. Non-qualified Defined Benefit Retirement Plans	Jun. 30, 2011 U.S. Non-qualified Defined Benefit Retirement Plans	Jun. 30, 2012 U.S. Non-qualified Defined Benefit Retirement Plans	Jun. 30, 2011 U.S. Non-qualified Defined Benefit Retirement Plans	Dec. 31, 2011 U.S. Non-qualified Defined Benefit Retirement Plans	Jun. 30, 2012 European Defined Benefit Retirement Plans	Jun. 30, 2011 European Defined Benefit Retirement Plans	Jun. 30, 2012 European Defined Benefit Retirement Plans	Jun. 30, 2011 European Defined Benefit Retirement Plans	Dec. 31, 2011 European Defined Benefit Retirement Plans	Jun. 30, 2012 United Kingdom defined benefit plan (the U.K. Plan)	Jun. 30, 2012 Postretirement Health Care and Life Insurance Benefit Plans	Jun. 30, 2011 Postretirement Health Care and Life Insurance Benefit Plans	Jun. 30, 2012 Postretirement Health Care and Life Insurance Benefit Plans	Jun. 30, 2011 Postretirement Health Care and Life Insurance Benefit Plans	Dec. 31, 2011 Postretirement Health Care and Life Insurance Benefit Plans	Dec. 31, 2011 U.S. Nonqualified Defined Benefit Retirement Plans	Jun. 30, 2012 U.S. Nonqualified Defined Benefit Retirement Plans
Net periodic benefit costs of defined benefit retirement plans
Service cost			$ 0.4	$ 0.3	$ 0.7	$ 0.5		$ 0.2	$ 0.2	$ 0.3	$ 0.9
Interest cost			0.2	0.2	0.5	0.5		1.6	1.8	3.3	3.6
Expected return on plan assets								(1.8)	(2.0)	(3.6)	(3.9)
Net amortization and deferral			0.5	0.3	1.1	0.6		0.2	0.1	0.4	0.3
Curtailment gain	(5.7)	(5.7)									(5.7)		(5.7)
Net periodic benefit cost			1.1	0.8	2.3	1.6		0.2	0.1	0.4	(4.8)
Amounts recognized on the balance sheet:
Accrued liabilities			0.3		0.3		0.3	3.1		3.1		0.4		0.7		0.7		0.7
Other non-current liabilities			34.3		34.3		33.1	25.8		25.8		28.6		7.1		7.1		7.3
Total accrued benefit			34.6		34.6		33.4	28.9		28.9		29.0		7.8		7.8		8.0
Reduction in projected plan obligation	1.6												1.6
Expected employer contribution in next fiscal year								7.8		7.8				0.3		0.3				0.3
Employer contribution to defined benefit retirement plans								$ 2.6	$ 2.5	$ 4.1	$ 3.9	$ 6.2		$ 0.1	$ 0.1	$ 0.1	$ 0.1	$ 0.3	$ 0.3