Loans Receivable (Summary of Information Related to New Consumer Loan Assignments) (Details) - USD ($) $ in Millions |
3 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
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| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | $ 1,903.3 | |||||||||||||
| Expected net cash flows at the time of assignment | [2] | $ 1,556.0 | 1,608.0 | [3] | |||||||||||
| Fair value at the time of assignment | [4] | 1,112.7 | |||||||||||||
| Provision for Credit Losses | 139.6 | 161.9 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | 580.9 | |||||||||||||
| Expected net Loan income at the time of assignment | [6] | 487.4 | 495.3 | ||||||||||||
| Dealer Loans [Member] | |||||||||||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | 1,339.7 | |||||||||||||
| Expected net cash flows at the time of assignment | [2] | 1,084.1 | 1,206.7 | [3] | |||||||||||
| Fair value at the time of assignment | [4] | 835.8 | |||||||||||||
| Provision for Credit Losses | 71.7 | 104.7 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | 423.0 | |||||||||||||
| Expected net Loan income at the time of assignment | [6] | 344.5 | 370.9 | ||||||||||||
| Purchased Loans [Member] | |||||||||||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | 563.6 | |||||||||||||
| Expected net cash flows at the time of assignment | [2] | 471.9 | 401.3 | [3] | |||||||||||
| Fair value at the time of assignment | [4] | 276.9 | |||||||||||||
| Provision for Credit Losses | 67.9 | 57.2 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | 157.9 | |||||||||||||
| Expected net Loan income at the time of assignment | [6] | 142.9 | 124.4 | ||||||||||||
| New Consumer Loan Assignments [Member] | |||||||||||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | 1,869.0 | |||||||||||||
| Expected net cash flows at the time of assignment | [3] | 1,556.0 | |||||||||||||
| Fair value at the time of assignment | [4] | 1,068.6 | |||||||||||||
| Provision for Credit Losses | 85.2 | 85.6 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | 572.6 | |||||||||||||
| New Consumer Loan Assignments [Member] | Dealer Loans [Member] | |||||||||||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | 1,200.0 | |||||||||||||
| Expected net cash flows at the time of assignment | [3] | 1,084.1 | |||||||||||||
| Fair value at the time of assignment | [4] | 739.6 | |||||||||||||
| Provision for Credit Losses | 43.4 | 52.1 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | 387.9 | |||||||||||||
| New Consumer Loan Assignments [Member] | Purchased Loans [Member] | |||||||||||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||||||||||||
| Contractual net cash flows at the time of assignment | [1] | 669.0 | |||||||||||||
| Expected net cash flows at the time of assignment | [3] | 471.9 | |||||||||||||
| Fair value at the time of assignment | [4] | 329.0 | |||||||||||||
| Provision for Credit Losses | 41.8 | $ 33.5 | |||||||||||||
| Expected future finance charges at the time of assignment | [5] | $ 184.7 | |||||||||||||
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