| **DERIVATIVES - Derivatives Designated in Hedge Relationships (Details) - Designated as hedging instrument - USD ($) $ in Thousands** | 6 Months Ended           | 12 Months Ended          |
|---------------------------------------------------------------------------------------------------------------------------------------|--------------------------|--------------------------|
||
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Notional Amount                                                                                                                       | $ 14,914,648             | $ 13,063,532             |
| Asset, Total                                                                                                                          | 12,752                   | 43,973                   |
| Liability, Total                                                                                                                      | $ 528,540                | $ 111,093                |
| Weighted Average Receive Rate                                                                                                         | 0.96%                    | 0.81%                    |
| Weighted Average Pay Rate                                                                                                             | 1.25%                    | 0.10%                    |
| Weighted Average                                                                                                                      |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Weighted Average Life (Years)                                                                                                         | 2 years 7 days           | 2 years 3 months         |
| Fair value hedges | Cross-currency swaps                                                                                              |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Notional Amount                                                                                                                       | $ 50,299                 | $ 14,743                 |
| Asset, Cash flow hedges                                                                                                               | 863                      | 655                      |
| Liability, Cash flow hedges                                                                                                           | $ 0                      | $ 0                      |
| Weighted Average Receive Rate                                                                                                         | 2.49%                    | 1.34%                    |
| Weighted Average Pay Rate                                                                                                             | 8.38%                    | 7.30%                    |
| Fair value hedges | Cross-currency swaps | Weighted Average                                                                           |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Weighted Average Life (Years)                                                                                                         | 6 years 2 months 4 days  | 1 year 10 months 2 days  |
| Fair value hedges | Interest rate swaps                                                                                               |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Notional Amount                                                                                                                       | $ 514,349                | $ 128,789                |
| Asset, Cash flow hedges                                                                                                               | 11,120                   | 1,188                    |
| Liability, Cash flow hedges                                                                                                           | $ 251                    | $ 0                      |
| Weighted Average Receive Rate                                                                                                         | 1.52%                    | 0.05%                    |
| Weighted Average Pay Rate                                                                                                             | 0.69%                    | 0.71%                    |
| Fair value hedges | Interest rate swaps | Weighted Average                                                                            |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Weighted Average Life (Years)                                                                                                         | 3 years 2 months 15 days | 3 years 7 months 2 days  |
| Cash flow hedges | Pay variable - receive fixed interest rate swaps                                                                   |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Notional Amount                                                                                                                       | $ 13,425,000             | $ 11,995,000             |
| Asset, Cash flow hedges                                                                                                               | 760                      | 41,980                   |
| Liability, Cash flow hedges                                                                                                           | $ 528,289                | $ 111,093                |
| Weighted Average Receive Rate                                                                                                         | 0.99%                    | 0.88%                    |
| Weighted Average Pay Rate                                                                                                             | 1.34%                    | 0.09%                    |
| Cash flow hedges | Pay variable - receive fixed interest rate swaps | Weighted Average                                                |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Weighted Average Life (Years)                                                                                                         | 2 years                  | 2 years 3 months 10 days |
| Cash flow hedges | Interest rate floors                                                                                               |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Notional Amount                                                                                                                       | $ 925,000                | $ 925,000                |
| Asset, Cash flow hedges                                                                                                               | 9                        | 150                      |
| Liability, Cash flow hedges                                                                                                           | $ 0                      | $ 0                      |
| Weighted Average Receive Rate                                                                                                         | 0.00%                    | 0.03%                    |
| Weighted Average Pay Rate                                                                                                             | 0.00%                    | 0.00%                    |
| Cash flow hedges | Interest rate floors | Weighted Average                                                                            |                     |                     |
| **Derivative [Line Items]**                                                                                                           |                     |                     |
| Weighted Average Life (Years)                                                                                                         | 1 year 3 months 14 days  | 1 year 8 months 4 days   |

| X                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Average fixed interest rate related to the group of interest rate derivatives.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAverageFixedInterestRate**Namespace Prefix:**us-gaap_**Data Type:**dtr-types:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAverageRemainingMaturity1**Namespace Prefix:**us-gaap_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Average variable interest rate related to the group of interest rate derivatives.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAverageVariableInterestRate**Namespace Prefix:**us-gaap_**Data Type:**dtr-types:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeInstrumentsInHedgesAssetsAtFairValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate fair value of all derivative liabilities designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeInstrumentsInHedgesLiabilitiesAtFairValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Nominal or face amount used to calculate payment on derivative.
+ References
Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value as of the balance sheet date of all interest rate derivative assets designated as cash flow hedging instruments.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959
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| X                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                               |
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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