v3.22.0.1
Loans - Summary of Changes in Allowance for Credit Losses (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Allowance for loan losses    
Balance, beginning of period $ 3,874 $ 2,168
Net (charge-offs)/recoveries (333) (907)
Provision 120 2,853
Other (88) (240)
Balance, end of period $ 3,573 $ 3,874
Allowance ratio 2.50% 3.70%
Net charge-off ratio 0.30% 0.90%
Allowance for losses on lending commitments    
Balance, beginning of period $ 557 $ 313
Provision 237 244
Other (18)  
Balance, end of period 776 557
Wholesale [Member]    
Allowance for loan losses    
Balance, beginning of period 2,584 1,331
Net (charge-offs)/recoveries (130) (615)
Provision (231) 2,108
Other (88) (240)
Balance, end of period $ 2,135 $ 2,584
Allowance ratio 1.60% 2.70%
Net charge-off ratio 0.10% 0.60%
Allowance for losses on lending commitments    
Balance, beginning of period $ 557 $ 313
Provision 50 244
Other (18)  
Balance, end of period 589 557
Consumer [Member]    
Allowance for loan losses    
Balance, beginning of period 1,290 837
Net (charge-offs)/recoveries (203) (292)
Provision 351 745
Other 0 0
Balance, end of period $ 1,438 $ 1,290
Allowance ratio 12.10% 15.90%
Net charge-off ratio 2.30% 4.20%
Allowance for losses on lending commitments    
Balance, beginning of period $ 0 $ 0
Provision 187 0
Other 0  
Balance, end of period $ 187 $ 0