| Disclosure of fee and commission income | During the three months ended September 30, 2023, and September 30, 2022, fee and commission income was comprised of:  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2023 |  
|  | Central Asia and Eastern Europe |  | Europe excluding Eastern Europe |  | The Unites States |  | Middle East/Caucasus |  | Total |  
|  |  |  |  |  |  |  |  |  |  |  
| Brokerage services | $ | 58,603 |  |  | $ | 24,038 |  |  | $ | 959 |  |  | $ | 1,113 |  |  | $ | 84,713 |  |  
| Commission income from payment processing  | 10,299 |  |  | — |  |  | — |  |  | — |  |  | 10,299 |  |  
| Bank services | 9,308 |  |  | — |  |  | — |  |  | — |  |  | 9,308 |  |  
| Underwriting and market-making services | 1,771 |  |  | — |  |  | 1,139 |  |  | — |  |  | 2,910 |  |  
| Other fee and commission income | 4,246 |  |  | 209 |  |  | 18 |  |  | — |  |  | 4,473 |  |  
| Total fee and commission income | $ | 84,227 |  |  | $ | 24,247 |  |  | $ | 2,116 |  |  | $ | 1,113 |  |  | $ | 111,703 |  | 
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2022 |  
|  | Central Asia and Eastern Europe |  | Europe excluding Eastern Europe |  | The Unites States |  | Middle East/Caucasus |  | Total |  
|  |  |  |  |  |  |  |  |  |  |  
| Brokerage service | $ | 11,512 |  |  | $ | 62,781 |  |  | $ | 1,050 |  |  | $ | — |  |  | $ | 75,343 |  |  
| Bank services | 5,779 |  |  | — |  |  | — |  |  | — |  |  | 5,779 |  |  
| Underwriting and market-making services | 1,587 |  |  | — |  |  | — |  |  | — |  |  | 1,587 |  |  
| Other fee and commission income | 189 |  |  | 259 |  |  | — |  |  | — |  |  | 448 |  |  
| Total fee and commission income | $ | 19,067 |  |  | $ | 63,040 |  |  | $ | 1,050 |  |  | $ | — |  |  | $ | 83,157 |  | 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Six months ended September 30, 2023 |  
|  | Central Asia and Eastern Europe |  | Europe excluding Eastern Europe |  | The Unites States |  | Middle East/Caucasus |  | Total |  
|  |  |  |  |  |  |  |  |  |  |  
| Brokerage service | $ | 93,621 |  |  | $ | 42,989 |  |  | $ | 2,072 |  |  | $ | 1,113 |  |  | $ | 139,795 |  |  
| Commission income from processing | 28,341 |  |  | — |  |  | — |  |  | — |  |  | 28,341 |  |  
| Bank services | 22,149 |  |  | — |  |  | — |  |  | — |  |  | 22,149 |  |  
| Underwriting and market-making services | 6,469 |  |  | — |  |  | 5,272 |  |  | — |  |  | 11,741 |  |  
| Other fee and commission income | 7,032 |  |  | 424 |  |  | 924 |  |  | — |  |  | 8,380 |  |  
| Total fee and commission income | $ | 157,612 |  |  | $ | 43,413 |  |  | $ | 8,268 |  |  | $ | 1,113 |  |  | $ | 210,406 |  | 
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Six months ended September 30, 2022 |  
|  | Central Asia and Eastern Europe |  | Europe excluding Eastern Europe |  | The Unites States |  | Middle East/Caucasus |  | Total |  
|  |  |  |  |  |  |  |  |  |  |  
| Brokerage service | $ | 15,115 |  |  | $ | 141,644 |  |  | $ | 2,184 |  |  | $ | — |  |  | $ | 158,943 |  |  
| Bank services | 9,592 |  |  | — |  |  | — |  |  | — |  |  | 9,592 |  |  
| Underwriting and market-making services | 3,230 |  |  | — |  |  | — |  |  | — |  |  | 3,230 |  |  
| Other fee and commission income | 322 |  |  | 516 |  |  | — |  |  | — |  |  | 838 |  |  
| Total fee and commission income | $ | 28,259 |  |  | $ | 142,160 |  |  | $ | 2,184 |  |  | $ | — |  |  | $ | 172,603 |  |  |