v3.26.1
Retained Earnings and Regulatory Capital Requirements - Capital Amounts and Ratios in Accordance With Current Banking Regulations (Details)
$ in Millions
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
HSBC USA    
Common equity Tier 1 ratio:    
Well-Capitalized Ratio 0.045  
Capital Amount $ 13,400 $ 13,100
Actual Ratio 0.121 0.121
Tier 1 capital ratio:    
Well-Capitalized Ratio 0.060  
Capital Amount $ 13,700 $ 13,300
Actual Ratio 0.123 0.124
Total capital ratio:    
Well-Capitalized Ratio 0.100  
Capital Amount $ 15,900 $ 15,600
Actual Ratio 0.143 0.144
Tier 1 leverage ratio:    
Well-Capitalized Ratio 0.040  
Capital Amount $ 13,700 $ 13,300
Actual Ratio 0.076 0.077
Risk weighted assets:    
Capital Amount $ 111,200 $ 107,900
Adjusted quarterly average assets    
Capital Amount $ 179,300 173,900
HSBC Bank USA    
Common equity Tier 1 ratio:    
Well-Capitalized Ratio 0.065  
Capital Amount $ 16,000 $ 15,600
Actual Ratio 0.159 0.159
Tier 1 capital ratio:    
Well-Capitalized Ratio 0.080  
Capital Amount $ 17,500 $ 17,100
Actual Ratio 0.174 0.175
Total capital ratio:    
Well-Capitalized Ratio 0.100  
Capital Amount $ 19,400 $ 19,000
Actual Ratio 0.193 0.194
Tier 1 leverage ratio:    
Well-Capitalized Ratio 0.050  
Capital Amount $ 17,500 $ 17,100
Actual Ratio 0.102 0.103
Risk weighted assets:    
Capital Amount $ 100,800 $ 97,800
Adjusted quarterly average assets    
Capital Amount $ 171,500 $ 166,200