Retirement Plans - Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
International
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation, end of year	$ 37.3	$ 31.7
Accumulated benefit obligation, end of year	36.9	31.4
Plan assets at fair value, end of year	25.8	25.1
United States
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation, end of year	88.3	92.2
Accumulated benefit obligation, end of year	88.3	92.2
Plan assets at fair value, end of year	$ 71.7	$ 69.6