Retirement Benefits Plans (Plan Assets in the Funded Defined Benefit Plan Measured at Fair Value, by Input Level) (Details) - Quoted Prices in Active Markets for Identical Assets (Level 1) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Plan assets in the funded defined benefit plan measured at fair value
Fair value of plan assets	$ 0.0	$ 39.8
Cash and cash equivalents
Schedule of Plan assets in the funded defined benefit plan measured at fair value
Fair value of plan assets	0.0	0.4
Fixed income securities | Fixed income securities | Fixed income securities
Schedule of Plan assets in the funded defined benefit plan measured at fair value
Fair value of plan assets	$ 0.0	$ 39.4