v3.25.2
Transactions Involving Related Parties - Narrative (Detail) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
AHM      
Related Party Transaction [Line Items]      
Dividends declared $ 1,900 $ 1,500 $ 1,300
AHFC | HMC      
Related Party Transaction [Line Items]      
Honda Motor Company required ownership interest (percentage) 80.00%    
HCFI | HMC      
Related Party Transaction [Line Items]      
Honda Motor Company required ownership interest (percentage) 80.00%    
HCFI | AHFC      
Related Party Transaction [Line Items]      
Dividends declared $ 74 37 125
HCFI | HCI      
Related Party Transaction [Line Items]      
Dividends declared $ 68 $ 34 $ 114