Leases (Assets and Liabilities Balance Related to Finance and Operating Leases) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Leases [Abstract]
Finance lease right-of-use assets	$ 1.4	$ 1.5
Operating lease right-of-use assets	18.6	18.9
Finance lease obligations, current portion	0.4	0.4
Finance lease obligations, non-current portion	1.0	1.1
Total finance lease obligations	1.4	1.5
Operating lease obligations, current portion	3.8	3.5
Operating lease obligations, non-current portion	15.1	15.4
Total operating lease obligations	$ 18.9	$ 18.9
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net of accumulated depreciation of $386.2 and $385.7	Property, plant and equipment, net of accumulated depreciation of $386.2 and $385.7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other accrued liabilities	Other accrued liabilities