Retirement Benefits Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined benefit plan (benefit) expense
Net settlement loss			$ (12.6)
Total expense			13.1	$ 0.1
Defined and Postretirement Benefit Plans
Defined benefit plan (benefit) expense
Reclassification of unrecognized losses from AOCI	$ (13.5)	$ 0.0	(13.5)	0.0
Recognized gain (loss) due to favorable settlement of defined benefit obligation	0.9
Defined benefit plan
Defined benefit plan (benefit) expense
Interest cost on benefit obligations	0.3	0.4	0.7	0.8
Expected return on plan assets	(0.2)	(0.5)	(0.6)	(0.9)
Amortization of actuarial losses	0.2	0.1	0.4	0.2
Net settlement loss	(12.6)	0.0	(12.6)	0.0
Total expense	$ 12.9	$ 0.0	$ 13.1	$ 0.1