Pension and Postretirement Plans Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Pension Plan [Member]
Prior service cost recognized:
Reclassification adjustments	$ 0.4	$ 0.2
Actuarial (loss) gain recognized:
Reclassification adjustments	24.9	17.3
Actuarial (loss) gain arising during the period	(20.9)	(57.5)
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost (benefit)	0.1
Actuarial loss	18.2
Total	18.3
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Prior service (cost) benefit, net of tax of ($0.1), ($0.2), $15.8, $21.3	(0.2)	(0.5)
Actuarial loss, net of tax of ($90.4), ($91.5), ($23.0), ($29.3)	(157.8)	(160.7)
Total	(158.0)	(161.2)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Effect [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Prior Service (Cost) Benefit, Tax Effect	(0.1)	(0.2)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), Tax Effect	(90.4)	(91.5)
Other Postretirement Benefit Plan [Member]
Prior service cost recognized:
Reclassification adjustments	(15.4)	(15.4)
Actuarial (loss) gain recognized:
Reclassification adjustments	5.4	5.4
Actuarial (loss) gain arising during the period	10.9	(12.9)
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost (benefit)	(14.8)
Actuarial loss	4.9
Total	(9.9)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Prior service (cost) benefit, net of tax of ($0.1), ($0.2), $15.8, $21.3	28.6	38.5
Actuarial loss, net of tax of ($90.4), ($91.5), ($23.0), ($29.3)	(40.9)	(50.9)
Total	(12.3)	(12.4)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Effect [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Prior Service (Cost) Benefit, Tax Effect	15.8	21.3
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), Tax Effect	$ (23.0)	$ (29.3)