| **LOANS AND ALLOWANCE FOR CREDIT LOSSES (As Restated) (Rollforward of Allowance for Credit Losses) (Details) - USD ($) $ in Thousands** | 3 Months Ended | 9 Months Ended |             |
|-----------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|-------------|
||
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | $ 2,834,653    | $ 1,297,655    | $ 1,701,602 | $ 834,337 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 937,165        | 766,663        | 2,951,055   | 1,698,889 |   |
| Other                                                                                                                                   |           | (61,220)       | (27,117)    | (61,220) |   |
| Charge-offs                                                                                                                             | (1,526,112)    | (1,001,970)    | (3,399,574) | (1,811,074) |   |
| Recoveries                                                                                                                              | 521,438        | 417,598        | 1,541,178   | 757,794 |   |
| Charge-offs, net of recoveries                                                                                                          | (1,004,674)    | (584,372)      | (1,858,396) | (1,053,280) |   |
| Allowance for loan losses, end of period                                                                                                | 2,767,144      | 1,418,726      | 2,767,144   | 1,418,726 |   |
| Reserve for unfunded lending commitments, beginning of period                                                                           | 137,641        | 170,274        | 132,641     | 220,000 |   |
| Provision for unfunded lending commitments                                                                                              | 0              | (20,000)       | 5,000       | (65,000) |   |
| Loss on unfunded lending commitments                                                                                                    | 0              | (633)          | 0           | (5,359) |   |
| Reserve for unfunded lending commitments, end of period                                                                                 | 137,641        | 149,641        | 137,641     | 149,641 |   |
| Total allowance for credit losses, end of period                                                                                        | 2,904,785      | 1,568,367      | 2,904,785   | 1,568,367 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 803,188        | 106,587        | 803,188     | 106,587 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 1,963,956      | 1,312,139      | 1,963,956   | 1,312,139 |   |
| **Financing receivables:**                                                                                                              |           |           |        |   |   |
| Ending balance                                                                                                                          | 81,573,906     | 74,777,082     | 81,573,906  | 74,777,082 |   |
| Ending balance, evaluated under the fair value option or lower of cost or fair value                                                    | 3,364,866      | 1,303,570      | 3,364,866   | 1,303,570 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 4,139,286      | 1,579,005      | 4,139,286   | 1,579,005 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 74,069,754     | 71,894,507     | 74,069,754  | 71,894,507 |   |
| Sale of TDRs and NPLs classified as held-for-sale                                                                                       |           | 484,000        |        |   |   |
| Commercial                                                                                                                              |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 402,695        | 369,893        | 401,553     | 443,074 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 26,337         | 25,317         | 64,491      | (5,095) |   |
| Other                                                                                                                                   |           | 0              | 0           | 0 |   |
| Charge-offs                                                                                                                             | (45,467)       | (28,686)       | (96,652)    | (81,163) |   |
| Recoveries                                                                                                                              | 25,091         | 8,844          | 39,264      | 18,552 |   |
| Charge-offs, net of recoveries                                                                                                          | (20,376)       | (19,842)       | (57,388)    | (62,611) |   |
| Allowance for loan losses, end of period                                                                                                | 408,656        | 375,368        | 408,656     | 375,368 |   |
| Reserve for unfunded lending commitments, beginning of period                                                                           | 137,641        | 170,274        | 132,641     | 220,000 |   |
| Provision for unfunded lending commitments                                                                                              | 0              | (20,000)       | 5,000       | (65,000) |   |
| Loss on unfunded lending commitments                                                                                                    | 0              | (633)          | 0           | (5,359) |   |
| Reserve for unfunded lending commitments, end of period                                                                                 | 137,641        | 149,641        | 137,641     | 149,641 |   |
| Total allowance for credit losses, end of period                                                                                        | 546,297        | 525,009        | 546,297     | 525,009 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 57,517         | 73,074         | 57,517      | 73,074 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 351,139        | 302,294        | 351,139     | 302,294 |   |
| **Financing receivables:**                                                                                                              |           |           |        |   |   |
| Ending balance                                                                                                                          | 39,825,473     | 35,683,463     | 39,825,473  | 35,683,463 |   |
| Ending balance, evaluated under the fair value option or lower of cost or fair value                                                    | 0              | 19,167         | 0           | 19,167 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 367,865        | 503,098        | 367,865     | 503,098 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 39,457,608     | 35,161,198     | 39,457,608  | 35,161,198 |   |
| Consumer                                                                                                                                |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 2,360,366      | 888,761        | 1,267,025   | 363,647 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 937,086        | 751,850        | 2,874,254   | 1,703,103 |   |
| Other                                                                                                                                   |           | (61,220)       | (27,117)    | (61,220) |   |
| Charge-offs                                                                                                                             | (1,480,645)    | (973,284)      | (3,302,922) | (1,729,911) |   |
| Recoveries                                                                                                                              | 496,347        | 408,754        | 1,501,914   | 739,242 |   |
| Charge-offs, net of recoveries                                                                                                          | (984,298)      | (564,530)      | (1,801,008) | (990,669) |   |
| Allowance for loan losses, end of period                                                                                                | 2,313,154      | 1,014,861      | 2,313,154   | 1,014,861 |   |
| Total allowance for credit losses, end of period                                                                                        | 2,313,154      | 1,014,861      | 2,313,154   | 1,014,861 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 745,671        | 33,513         | 745,671     | 33,513 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 1,567,483      | 981,348        | 1,567,483   | 981,348 |   |
| **Financing receivables:**                                                                                                              |           |           |        |   |   |
| Ending balance                                                                                                                          | 41,748,433     | 39,093,619     | 41,748,433  | 39,093,619 |   |
| Ending balance, evaluated under the fair value option or lower of cost or fair value                                                    | 3,364,866      | 1,284,403      | 3,364,866   | 1,284,403 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 3,771,421      | 1,075,907      | 3,771,421   | 1,075,907 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 34,612,146     | 36,733,309     | 34,612,146  | 36,733,309 |   |
| Consumer | Retail installment contracts and auto loans                                                                                  |           |           |        |   |   |
| **Financing receivables:**                                                                                                              |           |           |        |   |   |
| Loans held-for-sale                                                                                                                     |           |           |        |   | $ 1,000,000 |
| Unallocated                                                                                                                             |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 71,592         | 39,001         | 33,024      | 27,616 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | (26,258)       | (10,504)       | 12,310      | 881 |   |
| Other                                                                                                                                   |           |           | 0           |   |   |
| Charge-offs                                                                                                                             | 0              | 0              | 0           | 0 |   |
| Recoveries                                                                                                                              | 0              | 0              | 0           | 0 |   |
| Charge-offs, net of recoveries                                                                                                          | 0              | 0              | 0           | 0 |   |
| Allowance for loan losses, end of period                                                                                                | 45,334         | 28,497         | 45,334      | 28,497 |   |
| Total allowance for credit losses, end of period                                                                                        | 45,334         | 28,497         | 45,334      | 28,497 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 0              | 0              | 0           | 0 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 45,334         | 28,497         | 45,334      | 28,497 |   |
| **Financing receivables:**                                                                                                              |           |           |        |   |   |
| Ending balance                                                                                                                          | 0              | 0              | 0           | 0 |   |
| Ending balance, evaluated under the fair value option or lower of cost or fair value                                                    | 0              | 0              | 0           | 0 |   |
| Ending balance, individually evaluated for impairment                                                                                   | 0              | 0              | 0           | 0 |   |
| Ending balance, collectively evaluated for impairment                                                                                   | 0              | 0              | 0           | 0 |   |
| Retail installment contracts and auto loans                                                                                             |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 1,761,843      | 394,736        | 709,987     | 0 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 815,672        | 527,400        | 2,479,658   | 1,238,013 |   |
| Other                                                                                                                                   | 0              | (9,887)        | (27,117)    | (9,887) |   |
| Charge-offs                                                                                                                             | (940,942)      | (726,003)      | (2,484,560) | (1,339,083) |   |
| Recoveries                                                                                                                              | 470,710        | 372,983        | 1,429,315   | 670,186 |   |
| Charge-offs, net of recoveries                                                                                                          | (470,232)      | (353,020)      | (1,055,245) | (668,897) |   |
| Allowance for loan losses, end of period                                                                                                | 2,107,283      | 559,229        | 2,107,283   | 559,229 |   |
| Retail installment contracts and auto loans, purchased                                                                                  |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 542,709        | 0              | 963         | 0 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 129,109        | 240,616        | 958,738     | 540,855 |   |
| Other                                                                                                                                   | 0              | (9,887)        | (27,117)    | (9,887) |   |
| Charge-offs                                                                                                                             | (328,624)      | (557,995)      | (1,216,036) | (1,149,494) |   |
| Recoveries                                                                                                                              | 218,962        | 327,267        | 845,608     | 618,527 |   |
| Charge-offs, net of recoveries                                                                                                          | (109,662)      | (230,728)      | (370,428)   | (530,967) |   |
| Allowance for loan losses, end of period                                                                                                | 562,156        | 1              | 562,156     | 1 |   |
| Retail installment contracts and auto loans, originated                                                                                 |           |           |        |   |   |
| **Allowance for Loan Losses [Roll Forward]**                                                                                            |           |           |        |   |   |
| Allowance for loan losses, beginning of period                                                                                          | 1,219,134      | 394,736        | 709,024     | 0 |   |
| Provision for/ (Recovery of) loan losses                                                                                                | 686,563        | 286,784        | 1,520,920   | 697,158 |   |
| Other                                                                                                                                   | 0              | 0              | 0           | 0 |   |
| Charge-offs                                                                                                                             | (612,318)      | (168,008)      | (1,268,524) | (189,589) |   |
| Recoveries                                                                                                                              | 251,748        | 45,716         | 583,707     | 51,659 |   |
| Charge-offs, net of recoveries                                                                                                          | (360,570)      | (122,292)      | (684,817)   | (137,930) |   |
| Allowance for loan losses, end of period                                                                                                | $ 1,545,127    | $ 559,228      | $ 1,545,127 | $ 559,228 |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A valuation allowance for financing receivables that are expected to be uncollectible and reserve for unfunded lending commitments.
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No definition available.
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Net amount of direct write-downs and recoveries of financing receivables charged against the allowance.
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Gain (Loss) on Unfunded Commitments
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Increase (Decrease) in Allowance for Credit Losses from Sale of Troubled Debt Restructuring and Non-performing Loans Held-for-sale
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No definition available.
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Loans Receivable Held-for-sale, Net, Fair Value Option
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| - Definition
Net change in reserve for unfunded commitments which is included in the provision for credit losses.
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No definition available.
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Reserve for unfunded loan commitments and letters of credit.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of reduction of allowance reserve for credit loss arising from sale of loan and lease portfolios.
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| - Definition
A valuation allowance for financing receivables that are expected to be uncollectible.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.
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| - Definition
Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.
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| - Definition
Amount of recovery of financing receivables doubtful of collection that were previously charged off.
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| - Definition
A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
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No definition available.
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| - Definition
Amount of direct write-downs of financing receivables charged against the allowance.
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| - Definition
The balance of financing receivables that were collectively evaluated for impairment.
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The balance of financing receivables that were individually evaluated for impairment.
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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.
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No definition available.
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| - Definition
Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.
+ References
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| - Definition
Amount of expense related to estimated loss from loan and lease transactions.
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