BROKERAGE AND OTHER RECEIVABLES NET (Details) - USD ($) $ in Thousands  | 
Sep. 30, 2021  | 
Mar. 31, 2021  | 
|---|---|---|
| Brokerage and other receivables, net | $ 317,124 | $ 64,801 | 
| Margin lending receivables [Member] | ||
| Brokerage and other receivables, net | 308,256 | 58,095 | 
| Receivables from brokerage clients [Member] | ||
| Brokerage and other receivables, net | 4,134 | 4,199 | 
| Long-term installments receivables [Member] | ||
| Brokerage and other receivables, net | 1,210 | 1,280 | 
| Receivable for underwriting market-making services [Member] | ||
| Brokerage and other receivables, net | 887 | 564 | 
| Receivable from sale of securities [Member] | ||
| Brokerage and other receivables, net | 910 | 484 | 
| Dividends accrued [Member] | ||
| Brokerage and other receivables, net | 23 | 1,392 | 
| Bank commissions receivable [Member] | ||
| Brokerage and other receivables, net | 443 | 767 | 
| Other receivables [Member] | ||
| Brokerage and other receivables, net | 2,702 | 56 | 
| Allowance for receivables [Member] | ||
| Brokerage and other receivables, net | $ 1,441 | $ 2,036 | 
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- Definition Amount due from parties in nontrade transactions, classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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