| **FAIR VALUE (Fair Value Option for Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands** |             | 3 Months Ended | 9 Months Ended |            |            |
|------------------------------------------------------------------------------------------------------------|-------------|----------------|----------------|------------|------------|
||
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]**           |        |           |           |       |       |   |   |
| Mortgage servicing rights                                                                                  |        | $ 143,535      |           | $ 143,535  |       | $ 145,047 |   |
| Residential MSRs                                                                                           |        |           |           |       |       |   |   |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]**           |        |           |           |       |       |   |   |
| Mortgage servicing rights                                                                                  |        | 143,535        | $ 131,791      | 143,535    | $ 131,791  | $ 145,047 | $ 141,787 |
| Change in fair value due to valuation assumptions                                                          |        | (13,500)       | $ (2,700)      | 700        | $ (14,100) |   |   |
| Residential MSRs | MSRs                                                                                    |        |           |           |       |       |   |   |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]**           |        |           |           |       |       |   |   |
| Mortgage servicing rights                                                                                  |        | 143,535        |           | $ 143,535  |       |   |   |
| Loans held-for-sale                                                                                        |        |           |           |       |       |   |   |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]**           |        |           |           |       |       |   |   |
| Threshold period for discontinuing and reversing accrual of interest (more than)                           |        |           |           | 90 days    |       |   |   |
| **Fair Value**                                                                                             |        |           |           |       |       |   |   |
| Loans held-for-sale                                                                                        |        | 280,764        |           | $ 280,764  |       |   |   |
| Nonaccrual loans                                                                                           |        | 0              |           | 0          |       |   |   |
| **Aggregate Unpaid Principal Balance**                                                                     |        |           |           |       |       |   |   |
| Loans held-for-sale                                                                                        |        | 273,846        |           | 273,846    |       |   |   |
| Nonaccrual loans                                                                                           |        | 0              |           | 0          |       |   |   |
| **Difference**                                                                                             |        |           |           |       |       |   |   |
| Loans held-for-sale                                                                                        |        | 6,918          |           | 6,918      |       |   |   |
| Nonaccrual loans                                                                                           |        | 0              |           | 0          |       |   |   |
| Retail installment contracts held for investment                                                           |        |           |           |       |       |   |   |
| **Fair Value**                                                                                             |        |           |           |       |       |   |   |
| Retail installment contracts held for investment                                                           |        | 374,158        |           | 374,158    |       |   |   |
| Nonaccrual loans                                                                                           |        | 46,310         |           | 46,310     |       |   |   |
| **Aggregate Unpaid Principal Balance**                                                                     |        |           |           |       |       |   |   |
| Retail installment contracts held for investment                                                           |        | 496,200        |           | 496,200    |       |   |   |
| Nonaccrual loans                                                                                           |        | 72,279         |           | 72,279     |       |   |   |
| **Difference**                                                                                             |        |           |           |       |       |   |   |
| Retail installment contracts held for investment                                                           |        | (122,042)      |           | (122,042)  |       |   |   |
| Nonaccrual loans                                                                                           |        | $ (25,969)     |           | $ (25,969) |       |   |   |
| SCUSA | Retail installment contracts held for investment                                                   |        |           |           |       |       |   |   |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]**           |        |           |           |       |       |   |   |
| Threshold period for discontinuing and reversing accrual of interest (more than)                           | 60 days     |           |           | 60 days    |       |   |   |
| **Fair Value**                                                                                             |        |           |           |       |       |   |   |
| Retail installment contracts held for investment                                                           | $ 1,900,000 |           |           |       |       |   |   |
| **Aggregate Unpaid Principal Balance**                                                                     |        |           |           |       |       |   |   |
| Retail installment contracts held for investment                                                           | $ 2,600,000 |           |           |       |       |   |   |

| X                                                                                                                                                                                                                                                                                                      |
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Fair Value, Option, Loans Held as Assets, Aggregate Amount in Nonaccrual Status, Aggregate Unpaid Principal Balance
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| X                                                                                                                                                                                                                                                                                                                                  |
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Fair Value, Option, Loans Held for Sale, Aggregate Amount in Nonaccrual Status
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Fair Value, Option, Loans Held for Sale, Aggregate Amount in Nonaccrual Status, Aggregate Unpaid Principal Balance
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Fair Value, Option, Loans Held for Sale, Aggregate Amount in Nonaccrual Status, Aggregated Difference
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| - Definition
Unpaid principal balance of loans held-for-sale.
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| X                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold Period for Discontinuing and Reversing Interest Accrual
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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No definition available.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value.
+ References
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| - Definition
For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are in nonaccrual status.
+ References
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| - Definition
For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are 90 days or more past due, in nonaccrual status, or both.
+ References
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| - Definition
Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net Increase or Decrease in fair value as a result of changes in the inputs, assumptions, or model used to calculate the fair value of servicing assets.
+ References
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| X                                                                                                                           |
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