| TRADING AND AVAILABLE FOR SALE SECURITIES AT FAIR VALUE - Narrative (Details) | 6 Months Ended | 12 Months Ended | 
|---|---|---|
| Sep. 30, 2023  USD ($)  issuer | Mar. 31, 2023  USD ($)  issuer | |
| Defined Benefit Plan Disclosure [Line Items] | ||
| Number of issuers | issuer | 2 | 2 | 
| Other-than-temporary impairment in accumulated other comprehensive loss | $ 0 | $ 0 | 
| Kazakhstan Sustainability Fund JSC | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Percentage of trading securities | 10.00% | 10.00% | 
| Debt securities | $ 612,363,000 | $ 834,917,000 | 
| Ministry of Finance of the Republic of Kazakhstan | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Percentage of trading securities | 10.00% | 10.00% | 
| Debt securities | $ 2,310,780,000 | $ 1,015,161,000 | 
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- Definition Number of Debt Securities Issuers No definition available. 
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- Definition Percentage of Trading Securities No definition available. 
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- Definition Amount, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity), and investment in debt security measured at fair value with change in fair value recognized in net income (trading). Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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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. No definition available. 
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- Definition Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings and other comprehensive loss (OCI). Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Details 
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