Leases (Summary of Supplemental Cash Flow Information Related to Leases) (Parenthetical) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase of ROU asset upon modification	$ 8.6
ROU assets	0.6	$ 1.0	$ 3.2
Decrease of ROU asset upon modification	1.0
Right-of-use Asset [Member]
ROU assets	$ 3.7
Modified expected lease term	13 years