Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred income tax assets
Net operating loss tax carryovers	$ 184.1	$ 298.7
Pensions	51.7	94.3
Postretirement benefits other than pensions	51.5	69.8
Tax credits	42.0	40.2
Other items	95.6	103.9
Gross deferred income tax assets	424.9	606.9
Valuation allowance for deferred tax assets	(266.9)	(431.0)
Total deferred income tax assets	158.0	175.9
Deferred income tax liabilities
Bases of property, plant and equipment	122.2	114.0
Inventory valuation	17.1	32.5
Bases of amortizable intangible assets	9.0	18.0
Other items	23.0	24.7
Total deferred tax liabilities	171.3	189.2
Net deferred tax (liability)	$ (13.3)	$ (13.3)