Retirement and Other Postretirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
U.S. Non-qualified Defined Benefit Retirement Plans
Net periodic benefit costs of defined benefit retirement plans
Service cost	$ 0.7	$ 0.3
Interest cost	0.2	0.3
Net amortization and deferral	0.7	0.6
Net periodic benefit cost	1.6	1.2
Amounts recognized on the balance sheet:
Accrued liabilities	0.3		0.3
Other non-current liabilities	39.2		38.3
Total accrued benefit	39.5		38.6
Expected employer contribution in next fiscal year	0.3
Amount contributed			0.3
European Defined Benefit Retirement Plans
Net periodic benefit costs of defined benefit retirement plans
Service cost	0.1	0.1
Interest cost	1.7	1.7
Expected return on plan assets	(1.8)	(1.8)
Net amortization and deferral	0.2	0.2
Net periodic benefit cost	0.2	0.2
Amounts recognized on the balance sheet:
Accrued liabilities	3.5		0.4
Other non-current liabilities	32.4		36.1
Total accrued benefit	35.9		36.5
Expected employer contribution in next fiscal year	5.8
Amount contributed	1.5	1.6	5.7
Postretirement Health Care and Life Insurance Benefit Plans
Amounts recognized on the balance sheet:
Accrued liabilities	0.6		0.6
Other non-current liabilities	7.4		7.5
Total accrued benefit	8.0		8.1
Expected employer contribution in next fiscal year	0.6
Amount contributed	$ 0.1	$ 0.1	$ 0.3