Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Accrued postretirement benefits cost	$ 91.4	$ 88.0
Accrued pension cost	16.3	9.6
Inventory	0.7	12.0
Other employee benefit accruals	16.9	14.9
Tax loss and credit carryforwards	117.9	153.1
Other, net	60.0	44.6
Valuation allowances	(145.4)	(177.0)
Total deferred tax assets	157.8	145.2
Deferred tax liabilities - principally depreciation and amortization	(101.0)	(140.9)
Net deferred tax assets	$ 56.8	$ 4.3