| MARGIN LENDING, BROKERAGE AND OTHER RECEIVABLES, NET - Narrative (Details) $ in Thousands | Dec. 31, 2024  USD ($)  customer | Mar. 31, 2024  USD ($)  customer | 
|---|---|---|
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Collateral received, fair value | $ 4,478,894 | $ 2,824,498 | 
| Other receivables | 2,037,673 | 1,660,275 | 
| Accounts receivable, allowance for credit loss | 14,357 | 11,990 | 
| Margin lending receivables | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Other receivables | $ 2,020,426 | $ 1,635,377 | 
| Nonrelated Party | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Number of customers with a balance exceeding ten percent | customer | 3 | 1 | 
| Collateralized financings | $ 2,018,735 | $ 460,771 | 
| Nonrelated Party | Margin lending receivables | ||
| Schedule of Accounts, Notes, Loans and Financing Receivable [Table] | ||
| Other receivables | $ 1,433,546 | $ 399,196 | 
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- Definition Collateral Received, Fair Value No definition available. 
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- Definition Number Of Customers With A Margin Lending Balance Exceeding Ten Percent 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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