Leases (Summary of Lease Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Assets
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets, Noncurrent	Other Assets, Noncurrent
Operating right-of-use assets	$ 47.8	$ 34.0
Liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued liabilities	Accrued liabilities
Current lease liabilities	$ 7.2	$ 7.4
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Long-term lease liabilities	$ 42.6	$ 29.0
Total lease liabilities	$ 49.8	$ 36.4