Retirement Benefits Plans (Components of the Changes in Benefit Obligations and Fair Value of Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Current portion of retirement liabilities classified in accrued liabilities	$ 3.5	$ 3.7
Defined Benefit Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligations at beginning of year	39.9	32.9
Service cost	0.0	0.0
Interest cost	0.7	1.5	$ 1.3
Actuarial (gains) losses	(2.5)	7.2
Plan amendments	0.0	0.5
Curtailments	0.0	0.0
Benefits paid	(1.5)	(2.2)
Settlement of obligation	(36.6)	0.0
Benefit obligations at end of year	0.0	39.9	32.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	39.8	36.9
Actual (loss) income on plan assets	(1.0)	5.1
Benefits paid from plan assets	(1.5)	(2.2)
Transfer to defined contribution plan	(0.7)	0.0
Fair value of plan assets at end of year	0.0	39.8	36.9
Net asset (liability) at end of year	0.0	(0.1)
Postretirement Benefit Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligations at beginning of year	37.1	38.4
Service cost	0.0	0.2	0.3
Interest cost	1.3	1.5	1.4
Actuarial (gains) losses	1.4	1.2
Plan amendments	0.0	0.0
Curtailments	0.0	(1.4)
Benefits paid	(5.0)	(2.8)
Settlement of obligation	0.0	0.0
Benefit obligations at end of year	34.8	37.1	$ 38.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Benefits paid from plan assets	(5.0)	(2.8)
Net asset (liability) at end of year	$ (34.8)	$ (37.1)