Summary of Significant Accounting Policies (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Cash and cash equivalents	$ 8.4	$ 13.2	$ 8.1	$ 7.7
Restricted cash and cash equivalents	559.2	457.7	480.0	410.0
Total cash, cash equivalents, restricted cash and restricted cash equivalents	$ 567.6	$ 470.9	$ 488.1	$ 417.7