Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) segment
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment			1		1
Uninsured cash and cash equivalents	$ 2.8		$ 2.8		$ 7.1
Total provision for credit losses	250.5	$ 147.5	387.9	$ 170.8
Restricted Cash and Cash Equivalents [Member]
Summary Of Significant Accounting Policies [Line Items]
Uninsured cash and cash equivalents	405.0		405.0		$ 406.5
New Consumer Loan Assignments [Member]
Summary Of Significant Accounting Policies [Line Items]
Total provision for credit losses	81.7	97.5	174.8	200.1
Loans Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Total provision for credit losses	$ 0.0	$ 0.0	$ 0.0	$ 0.0