ASSETS AND LIABILITIES HELD FOR SALE - Balance Sheet (Details) - USD ($) $ in Thousands  | 
Mar. 31, 2022  | 
Mar. 31, 2021  | 
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| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | ||
| Total assets held for sale | $ 825,419 | $ 748,048 | 
| Total liabilities held for sale | 812,478 | 676,568 | 
| As recast | ||
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | ||
| Cash and cash equivalents | 428,480 | 531,791 | 
| Restricted cash | 28,406 | 27,594 | 
| Trading securities | 122,497 | 148,642 | 
| Brokerage and other receivables, net | 210,087 | 15,575 | 
| Loans issued | 2,395 | 2,041 | 
| Other assets | 33,554 | 22,405 | 
| Total assets held for sale | 825,419 | 748,048 | 
| Customer liabilities | 701,584 | 573,181 | 
| Debt securities issued | 64,637 | 37,095 | 
| Securities repurchase agreement obligations | 32,469 | 51,997 | 
| Other liabilities | 13,788 | 14,295 | 
| Total liabilities held for sale | $ 812,478 | $ 676,568 | 
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- Definition Disposal Group, Including Discontinued Operation, Customer Liabilities No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Debt securities Issued No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Loans Issued No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Restricted Cash No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Securities Repurchase Agreement Obligations No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Trading Securities No definition available. 
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- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount classified as accounts, notes and loans receivable attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount classified as cash and cash equivalents attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount classified as other assets attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount classified as other liabilities attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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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 classified as liabilities attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Details 
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