Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets
Pensions	$ 158.0	$ 294.9
Postretirement benefits other than pensions	86.5	129.5
Net operating loss tax carryovers	336.1	407.8
Tax credits	92.6	56.7
Deferred compensation and other benefit plans	13.8	25.7
Other items	55.9	107.4
Gross deferred income tax assets	742.9	1,022.0
Valuation allowance for deferred tax assets	(274.0)	(291.4)
Total deferred income tax assets	468.9	730.6
Deferred income tax liabilities
Bases of property, plant and equipment	375.3	547.1
Inventory valuation	50.0	77.6
Bases of amortizable intangible assets	38.7	65.6
Other items	7.0	43.9
Total deferred tax liabilities	471.0	734.2
Net deferred tax liability	$ (2.1)	$ (3.6)