Accumulated Other Comprehensive Income (Loss) Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	$ (250.1)	$ (196.6)
Other comprehensive (loss) income before reclassifications	(7.8)	5.7
Amounts reclassified from accumulated other comprehensive loss (net of tax $(6.6) and $(8.0))	19.1	12.5
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	(6.6)	(8.0)
Actuarial loss, (net of tax $0.5 and $18.0)	(1.5)	(28.2)
Net Unamortized Gain (Loss) Arising During Period, Tax	0.5	18.0
Net current-period other comprehensive (loss) income	9.8	(10.0)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0.0	(43.5)
Ending Balance December 31,	(240.3)	(250.1)
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	(4.6)	(10.3)
Other comprehensive (loss) income before reclassifications	(7.8)	5.7
Amounts reclassified from accumulated other comprehensive loss (net of tax $(6.6) and $(8.0))	0.0	0.0
Actuarial loss, (net of tax $0.5 and $18.0)	0.0	0.0
Net current-period other comprehensive (loss) income	(7.8)	5.7
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0.0	0.0
Ending Balance December 31,	(12.4)	(4.6)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	(245.5)	(186.3)
Other comprehensive (loss) income before reclassifications	0.0	0.0
Amounts reclassified from accumulated other comprehensive loss (net of tax $(6.6) and $(8.0))	19.1	12.5
Actuarial loss, (net of tax $0.5 and $18.0)	(1.5)	(28.2)
Net current-period other comprehensive (loss) income	17.6	(15.7)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0.0	(43.5)
Ending Balance December 31,	$ (227.9)	$ (245.5)