v3.25.1
Related Party Transactions - Summary of Related Party Transactions (Income - Expense) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Income (Expense):    
Interest income $ 1,880 $ 1,893
Net interest income 526 426
Trading revenue (expense) 193 276
Servicing and other fees from HSBC affiliates:    
Gain (loss) on instruments designated at fair value and related derivatives (3) (20)
Support services from HSBC affiliates:    
Total support services from HSBC affiliates (404) (399)
Related Party    
Income (Expense):    
Interest income 71 54
Interest expense (162) (130)
Net interest income (91) (76)
Trading revenue (expense) (484) (2,020)
Servicing and other fees from HSBC affiliates:    
Gain (loss) on instruments designated at fair value and related derivatives (187) 125
Support services from HSBC affiliates:    
Total support services from HSBC affiliates (404) (399)
Rental income from HSBC affiliates, net 12 14
Stock based compensation expense (8) (9)
HSBC Technology & Services (USA) Inc. ("HTSU")    
Support services from HSBC affiliates:    
Total support services from HSBC affiliates (226) (235)
HSBC Markets (USA) Inc. ("HMUS")    
Support services from HSBC affiliates:    
Total support services from HSBC affiliates (55) (56)
Other HSBC affiliates    
Support services from HSBC affiliates:    
Total support services from HSBC affiliates (123) (108)
Servicing and other fees from HSBC affiliates    
Servicing and other fees from HSBC affiliates:    
Other revenues 102 88
Servicing and other fees from HSBC affiliates | Related Party    
Servicing and other fees from HSBC affiliates:    
Other revenues 102 88
Servicing and other fees from HSBC affiliates | HSBC Bank plc    
Servicing and other fees from HSBC affiliates:    
Other revenues 67 48
Servicing and other fees from HSBC affiliates | HSBC Markets (USA) Inc. ("HMUS")    
Servicing and other fees from HSBC affiliates:    
Other revenues 18 23
Servicing and other fees from HSBC affiliates | Other HSBC affiliates    
Servicing and other fees from HSBC affiliates:    
Other revenues $ 17 $ 17