| MARGIN LENDING, BROKERAGE AND OTHER RECEIVABLES, NET - Narrative (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Mar. 31, 2024 | 
|---|---|---|
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Collateral received, fair value | $ 5,845,654 | $ 7,579,057 | 
| Collateralized financings | 2,934,515 | 2,516,108 | 
| Other receivables | 1,623,962 | 1,660,275 | 
| Accounts receivable, allowance for credit loss | 14,069 | 11,990 | 
| Margin lending receivables | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Other receivables | $ 1,587,112 | $ 1,635,377 | 
| One | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Collateral, percentage | 50.00% | 33.00% | 
| One | Margin lending receivables | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Other receivables | $ 680,078 | $ 399,196 | 
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- Definition Collateral, Percentage No definition available. 
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- Definition Collateral Received, Fair Value No definition available. 
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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. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount of allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition The value of the collateral (typically cash) that the entity receives in a financing transaction in exchange for securities lent. This item represents a liability in the financial statements of the lender of the securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount due from parties in nontrade transactions, classified as other. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Details 
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