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Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 USD ($) segment | Mar. 31, 2023 USD ($) | Dec. 31, 2023 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |  |
Number of reportable segments | segment | 1 |  |
Uninsured cash and cash equivalents | $ 8.1 |  | $ 12.8
Total provision for credit losses | 186.0 | $ 137.4 |
Restricted Cash and Cash Equivalents [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Uninsured cash and cash equivalents | 554.7 |  | $ 453.7
New Consumer Loan Assignments [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Total provision for credit losses | 98.8 | 93.1 |
Loans Receivable [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Total provision for credit losses | $ 0.0 | $ 0.0 |

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