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Loans Receivable Loans Receivable (Summary of Provision for Credit Losses) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2026 | Mar. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | $ 139.6 | $ 161.9
Dealer Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 71.7 | 104.7
Purchased Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 67.9 | 57.2
New Consumer Loan Assignments [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 85.2 | 85.6
New Consumer Loan Assignments [Member] | Dealer Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 43.4 | 52.1
New Consumer Loan Assignments [Member] | Purchased Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 41.8 | 33.5
Forecast Changes [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 54.4 | 76.3
Forecast Changes [Member] | Dealer Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | 28.3 | 52.6
Forecast Changes [Member] | Purchased Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Provision for Credit Losses | $ 26.1 | $ 23.7

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