Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Net operating loss carryforwards	$ 14.0	$ 21.4
Tax credit carryforwards	1.5	2.0
Pension and deferred compensation	31.6	35.3
Royalty acceleration	45.1	0.0
Other	12.2	11.0
Valuation allowance	(12.2)	(15.1)
Total deferred tax assets	92.2	54.6
Deferred tax liabilities:
Property, plant, and equipment	47.2	42.1
Tax on undistributed earnings of subsidiaries	1.8	6.5
Other	(0.4)	0.4
Total deferred tax liabilities	48.6	49.0
Net deferred tax asset (liability)	$ 43.6	$ 5.6