v3.26.1
Legal proceedings and regulatory matters (Details)
$ in Millions, $ in Millions
 1 Months Ended 6 Months Ended
Sep. 30, 2025
USD ($)
Feb. 29, 2024
USD ($)
May 31, 2023
USD ($)
employee
Jun. 30, 2026
USD ($)
action
employee
bankingRelationship
company
trust
Dec. 31, 2026
CAD ($)
Dec. 31, 2025
USD ($)
Oct. 31, 2025
USD ($)
Sep. 29, 2025
USD ($)
Mar. 31, 2024
employee
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       $ 125,712   $ 120,324      
Provisions       $ 2,942   3,441      
Number of mortgage securitisation trusts (more than) | trust       280          
US Anti-Terrorism Act litigation                  
Disclosure of contingent liabilities [line items]                  
Number of hearings | action       6          
Number of claims dismissed | action       2          
Loss contingency, number of hearings in early procedural stage | action       4          
Benchmark rate litigation                  
Disclosure of contingent liabilities [line items]                  
Actions seeking damages | action       2          
Forex litigation                  
Disclosure of contingent liabilities [line items]                  
Damages sought   $ 3,000              
Investigations involving HSBC Private Bank (Suisse) SA                  
Disclosure of contingent liabilities [line items]                  
Number of historical banking relationships | bankingRelationship       2          
Precious metals fix-related investigations and litigation                  
Disclosure of contingent liabilities [line items]                  
Damages sought     $ 1,000            
Employees involved in litigation | employee     7 1          
Number of companies involved in litigation | company       2          
US mortgage securitisation litigation                  
Disclosure of contingent liabilities [line items]                  
Number of pending actions | action       1          
Legal proceedings and regulatory matters                  
Disclosure of contingent liabilities [line items]                  
Provisions       $ 1,277   $ 1,662      
Hongkong and Shanghai Banking Corporation | Korean short selling investigation                  
Disclosure of contingent liabilities [line items]                  
Number of employees | employee                 3
Madoff Securities                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       184       $ 508  
Madoff Securities | HSBC Private Bank (Suisse) SA                  
Disclosure of contingent liabilities [line items]                  
Contingent liabilities dismissed $ 292                
Madoff Securities | HSBC Bank USA, N.A.                  
Disclosure of contingent liabilities [line items]                  
Contingent liabilities dismissed $ 32                
Fairfield                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       367          
Herald Fund SPC                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       5,600          
Herald Fund SPC | Cash and securities                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       521          
Herald Fund SPC | HSBC Securities Services (Luxembourg) S.A. | Legal proceedings and regulatory matters                  
Disclosure of contingent liabilities [line items]                  
Provisions             $ 1,100    
Alpha Prime Fund Limited                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       3,300          
Alpha Prime Fund Limited | Restitution of Securities                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       1,000          
Senator Fund SPC                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities       $ 1,400          
Ontario and Quebec superior courts                  
Disclosure of contingent liabilities [line items]                  
Estimated financial effect of contingent liabilities         $ 1,000        
Punitive damages         $ 250