Pension and Postretirement Plans Projected Benefit Obligation (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at December 31,	$ 435.3	$ 410.6
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1,	523.0	584.9
Service cost	1.0	2.1	2.6
Interest Cost	21.0	18.8	21.3
Prior service credit	0	0
Actuarial (gain) loss	73.5	(38.2)
Benefits paid	(41.2)	(44.6)
Retiree drug subsidy received	0	0
Other	0	0
Benefit obligation at December 31,	577.3	523.0	584.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1,	399.3	343.8
Actual return on plan assets	44.2	55.1
Employer contributions	22.0	45.0
Retiree drug subsidy received	0	0
Benefits paid	(41.2)	(44.6)
Fair value of plan assets at December 31,	424.3	399.3	343.8
Unfunded status	(153.0)	(123.7)
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1,	101.5	152.4
Service cost	0.3	0.4	0.5
Interest Cost	4.0	4.0	5.6
Prior service credit	0	(17.4)
Actuarial (gain) loss	13.3	(19.6)
Benefits paid	(15.2)	(23.9)
Retiree drug subsidy received	0.5	0.5
Other	4.6	5.1
Benefit obligation at December 31,	109.0	101.5	152.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1,	11.3	11.7
Actual return on plan assets	0.4	0.4
Employer contributions	14.0	22.6
Retiree drug subsidy received	0.5	0.5
Benefits paid	(15.2)	(23.9)
Fair value of plan assets at December 31,	11.0	11.3	11.7
Unfunded status	$ (98.0)	$ (90.2)