v3.26.1
Fair Value Measurements - Summary of Carrying Values and Fair Values of Financial Instruments Except for those Measured at Fair Value on a Recurring Basis (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Assets    
Dealer loans, net, carrying value $ 4,687 $ 4,694
Retail loans, net, carrying value 50,201 49,649
Liabilities    
Commercial paper, carrying value 5,638 2,929
Bank loans, carrying value 2,355 2,382
Medium term note programs, carrying value 39,084 40,726
Other debt, carrying value 3,199 3,407
Secured debt, carrying value 14,908 15,344
Fair value    
Assets    
Dealer loans, net 4,346 4,222
Retail loans, net 50,197 49,713
Liabilities    
Commercial paper 5,638 2,929
Bank loans 2,356 2,374
Public MTN Program 38,841 40,411
Other debt 3,236 3,425
Secured debt 14,918 15,395
Level 1 | Fair value    
Assets    
Dealer loans, net 0 0
Retail loans, net 0 0
Liabilities    
Commercial paper 0 0
Bank loans 0 0
Public MTN Program 0 0
Other debt 0 0
Secured debt 0 0
Level 2 | Fair value    
Assets    
Dealer loans, net 0 0
Retail loans, net 0 0
Liabilities    
Commercial paper 5,638 2,929
Bank loans 2,356 2,374
Public MTN Program 38,841 40,411
Other debt 3,236 3,425
Secured debt 14,918 15,395
Level 3 | Fair value    
Assets    
Dealer loans, net 4,346 4,222
Retail loans, net 50,197 49,713
Liabilities    
Commercial paper 0 0
Bank loans 0 0
Public MTN Program 0 0
Other debt 0 0
Secured debt $ 0 $ 0