Related party transactions - Summary of shareholdings, options and other securities of key management personnel (Details) $ in Thousands |
Dec. 31, 2025
shares
USD ($)
|
Dec. 31, 2024
shares
USD ($)
|
Dec. 31, 2023
shares
|
|---|---|---|---|
| Disclosure of transactions between related parties [line items] | |||
| Number of options held over HSBC Holdings ordinary shares under employee share plans | 58,902,349 | 75,335,399 | 83,994,000 |
| Key management personnel of entity or parent | |||
| Disclosure of transactions between related parties [line items] | |||
| Number of options held over HSBC Holdings ordinary shares under employee share plans | $ | 0 | 20 | |
| Number of HSBC Holdings ordinary shares held beneficially and non-beneficially | 14,817,000 | 17,455,000 | |
| Number of other HSBC securities held (in shares) | 0 | 228,000 | |
| Shareholdings, options and other securities of key management personnel (in shares) | 14,817,000 | 17,703,000 |