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Loans Receivable (Write-Offs Segmented by Year of Assignment) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Write-offs | $ 0.0 | $ 0.0 | $ 0.0 | $ 0.0
Dealer Loans [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Write-offs | 0.0 | 0.0 | 0.0 | 0.0
Purchased Loans [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Write-offs | 0.0 | 0.0 | 0.0 | 0.0
Allowance for Credit Losses [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff | 87.1 | 75.1 | 287.1 | 244.0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff | 53.2 | 45.4 | 157.3 | 140.6
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff | 93.4 | 55.9 | 257.5 | 170.5
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff | 62.8 | 80.4 | 168.8 | 235.7
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff | 42.4 | 48.1 | 125.7 | 143.8
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff | 23.9 | 21.9 | 39.3 | 32.6
Write-offs | 362.8 | 326.8 | 1,035.7 | 967.2
Allowance for Credit Losses [Member] | Dealer Loans [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff | 63.2 | 43.4 | 206.3 | 135.0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff | 40.3 | 27.9 | 112.7 | 82.0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff | 70.0 | 33.2 | 180.8 | 97.1
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff | 29.9 | 47.0 | 65.3 | 126.1
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff | 14.1 | 11.5 | 39.0 | 33.7
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff | 4.4 | 4.0 | 9.0 | 7.1
Write-offs | 221.9 | 167.0 | 613.1 | 481.0
Allowance for Credit Losses [Member] | Purchased Loans [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] |  |  |  |
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff | 23.9 | 31.7 | 80.8 | 109.0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff | 12.9 | 17.5 | 44.6 | 58.6
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff | 23.4 | 22.7 | 76.7 | 73.4
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff | 32.9 | 33.4 | 103.5 | 109.6
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff | 28.3 | 36.6 | 86.7 | 110.1
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff | 19.5 | 17.9 | 30.3 | 25.5
Write-offs | $ 140.9 | $ 159.8 | $ 422.6 | $ 486.2

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