v3.22.0.1
Regulation and Capital Adequacy - CET1, Tier 1 Capital and Tier 2 Capital (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Change in allowance for credit losses $ 82 $ (2,630)
Standardized Capital Rules [Member]    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
CET 1, Beginning balance 81,641 74,850
Change in Impact of CECL transition (21) 1,126
Change in common shareholders' equity 14,494 5,667
Change in deduction for goodwill 42 (123)
Change in deduction for identifiable intangible assets 200 3
Change in other adjustments (102) 118
CET 1, Ending balance 96,254 81,641
Tier 1 Capital, Beginning balance 92,730 85,440
Change in CET1 14,613 6,791
Change in deduction for investments in covered funds (83) 504
Change in preferred stock (500)  
Change in other adjustments 6 (5)
Tier 1 Capital, Ending balance 106,766 92,730
Tier 2 capital, Beginning balance 15,424 14,925
Change in qualifying subordinated debt (642) (651)
Change in junior subordinated debt (94) (96)
Change in allowance for credit losses (61) 1,293
Change in other adjustments 9 (47)
Tier 2 Capital, Ending balance 14,636 15,424
Total capital 121,402 108,154
Advanced Capital Rules [Member]    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
CET 1, Beginning balance 81,641 74,850
Change in Impact of CECL transition (21) 1,126
Change in common shareholders' equity 14,494 5,667
Change in deduction for goodwill 42 (123)
Change in deduction for identifiable intangible assets 200 3
Change in other adjustments (102) 118
CET 1, Ending balance 96,254 81,641
Tier 1 Capital, Beginning balance 92,730 85,440
Change in CET1 14,613 6,791
Change in deduction for investments in covered funds (83) 504
Change in preferred stock (500)  
Change in other adjustments 6 (5)
Tier 1 Capital, Ending balance 106,766 92,730
Tier 2 capital, Beginning balance 13,279 13,473
Change in qualifying subordinated debt (642) (651)
Change in junior subordinated debt (94) (96)
Change in allowance for credit losses 0 0
Change in other adjustments (492) 553
Tier 2 Capital, Ending balance 12,051 13,279
Total capital $ 118,817 $ 106,009