Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Accrued employee benefits and compensation	$ 7.7	$ 8.7
Net operating loss carryforwards	11.8	4.4
Tax credit carryforwards	6.7	2.8
Reserves and accruals	5.7	4.7
Operating leases	3.6	4.2
Capitalized research and development	25.6	21.3
Other	6.9	10.2
Total deferred tax assets	68.0	56.3
Less deferred tax asset valuation allowance	(11.4)	(2.8)	$ (9.8)	$ (9.3)
Total deferred tax assets, net of valuation allowance	56.6	53.5
Deferred tax liabilities
Depreciation and amortization	17.7	14.4
Postretirement benefit obligations	0.7	0.7
Unremitted earnings	1.5	2.6
Operating leases	4.1	4.6
Other	5.8	4.2
Total deferred tax liabilities	29.8	26.5
Net deferred tax asset (liability)	$ 26.8	$ 27.0