Leases (Summary of Supplemental Balance Sheet Information Related to Operating Leases) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
ROU assets	$ 34.5	$ 35.3	$ 29.2
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Current lease liabilities	$ 5.2	$ 5.2
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent
Non-current lease liabilities	$ 29.3	$ 30.1
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent