Retirement Plans - Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
United States
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation, end of year	$ 64.9	$ 72.8
Accumulated benefit obligation, end of year	64.9	72.8
Plan assets at fair value, end of year	49.8	59.1
International
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation, end of year	24.1	22.8
Accumulated benefit obligation, end of year	24.1	22.8
Plan assets at fair value, end of year	$ 15.2	$ 15.8