Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income Components Reclassification [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	$ (213.6)	$ (0.7)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(87.3)	(1.1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	224.9	20.5
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(482.5)	(626.1)
Income tax (benefit) expense	(60.3)	(6.8)
Net current period other comprehensive (loss) income, net of income taxes	77.3	12.6
Other Comprehensive Income (loss), net of tax, prior to distribution of spinoff	77.3	12.6
Other Comprehensive (Income) Loss, Net of Tax, Portion Attributable to Noncontrolling Interest		(0.5)
Accumulated Other Comprehensive Income (Loss) Attributable to Spinoff		0
Net current period comprehensive (loss) income, net of income taxes and non-controlling interest	77.3	12.1
Ending Balance	(405.2)	(614.0)
Foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income Components Reclassification [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(27.8)	(0.6)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(0.7)	37.5
Income tax (benefit) expense	0	0
Net current period other comprehensive (loss) income, net of income taxes	(27.8)	(0.6)
Other Comprehensive (Income) Loss, Net of Tax, Portion Attributable to Noncontrolling Interest		(0.5)
Accumulated Other Comprehensive Income (Loss) Attributable to Spinoff		0
Net current period comprehensive (loss) income, net of income taxes and non-controlling interest	(27.8)	(1.1)
Ending Balance	(28.5)	36.4
Pension and postretirement liability adjustment [Member]
Accumulated Other Comprehensive Income Components Reclassification [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(60.1)	(0.3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	225.5	20.3
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(481.0)	(663.2)
Income tax (benefit) expense	(60.3)	(6.8)
Net current period other comprehensive (loss) income, net of income taxes	105.1	13.2
Other Comprehensive (Income) Loss, Net of Tax, Portion Attributable to Noncontrolling Interest		0
Accumulated Other Comprehensive Income (Loss) Attributable to Spinoff		0
Net current period comprehensive (loss) income, net of income taxes and non-controlling interest	105.1	13.2
Ending Balance	(375.9)	(650.0)
Derivative financial instruments fair value adjustment [Member]
Accumulated Other Comprehensive Income Components Reclassification [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0.6	(0.2)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(0.6)	0.2
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(0.8)	(0.4)
Income tax (benefit) expense	0	0
Net current period other comprehensive (loss) income, net of income taxes	0	0
Other Comprehensive (Income) Loss, Net of Tax, Portion Attributable to Noncontrolling Interest		0
Accumulated Other Comprehensive Income (Loss) Attributable to Spinoff
Net current period comprehensive (loss) income, net of income taxes and non-controlling interest	0	0
Ending Balance	$ (0.8)	$ (0.4)