Regulation and Capital Adequacy - CET1, Tier 1 Capital and Tier 2 Capital (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Tier 2 capital
Allowance for credit losses	$ (318)	$ (72)	$ (1,240)	$ 266
Standardized
CET1 capital
Beginning balance			96,254	81,641	$ 81,641
Common shareholders’ equity			9,364		14,494
Impact of CECL transition			(276)		(21)
Deduction for goodwill			(1,996)		42
Deduction for identifiable intangible assets			(1,316)		200
Other adjustments			(3,323)		(102)
Ending balance	98,707		98,707		96,254
Tier 1 capital
Beginning balance			106,766	92,730	92,730
CET1 capital			2,453		14,613
Deduction for investments in covered funds			(4)		(83)
Preferred stock					(500)
Other adjustments			(1)		6
Ending balance	109,214		109,214		106,766
Tier 2 capital
Beginning balance			14,636	15,424	15,424
Qualifying subordinated debt			(543)		(642)
Junior subordinated debt			(94)		(94)
Allowance for credit losses			1,564		(61)
Other adjustments			36		9
Ending balance	15,599		15,599		14,636
Total capital	124,813		124,813		121,402
Advanced
CET1 capital
Beginning balance			96,254	81,641	81,641
Common shareholders’ equity			9,364		14,494
Impact of CECL transition			(276)		(21)
Deduction for goodwill			(1,996)		42
Deduction for identifiable intangible assets			(1,316)		200
Other adjustments			(3,323)		(102)
Ending balance	98,707		98,707		96,254
Tier 1 capital
Beginning balance			106,766	92,730	92,730
CET1 capital			2,453		14,613
Deduction for investments in covered funds			(4)		(83)
Preferred stock					(500)
Other adjustments			(1)		6
Ending balance	109,214		109,214		106,766
Tier 2 capital
Beginning balance			12,051	$ 13,279	13,279
Qualifying subordinated debt			(543)		(642)
Junior subordinated debt			(94)		(94)
Allowance for credit losses			0		0
Other adjustments			1,141		(492)
Ending balance	12,555		12,555		12,051
Total capital	$ 121,769		$ 121,769		$ 118,817