Summary of Significant Accounting Policies (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 3.2	$ 7.7	$ 4.1	$ 23.3
Restricted cash and cash equivalents	408.8	410.0	426.7	410.9
Total cash, cash equivalents, restricted cash and restricted cash equivalents	$ 412.0	$ 417.7	$ 430.8	$ 434.2