Fair Value Measurements - Changes in Fair Value of Level 3 Assets and Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivatives liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total liabilities, ending balance	$ (487)	$ (247)		$ (487)	$ (247)
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total assets, beginning balance	(199)	130		145	319
Assets, Total Realized/Unrealized Gains (Losses) Included in Earnings	(65)	(144)		(431)	(330)
Assets, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	(5)	(2)		(9)	(3)
Assets, Purchases	0	0		0	0
Assets, Issuances	1	1		3	7
Assets, Settlements	26	260		(12)	296
Assets, Transfers Into Level 3	(17)	(38)		2	(30)
Assets Transfers out of Level 3	9	0		52	(52)
Total assets, ending balance	(250)	207	$ 130	(250)	207
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	(63)	(1)		(343)	4
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	(5)	(2)		(9)	(3)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total liabilities, beginning balance	(2,593)	(1,512)		(2,388)	(1,094)
Total Realized/Unrealized Gains (Losses) Included in Earnings	89	42		487	11
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	1		17	1
Purchases	0	0		0	0
Issuances	(367)	(660)		(1,025)	(1,201)
Settlements	222	112		538	323
Transfers Into Level 3	(161)	(9)		(528)	(154)
Transfers Out of Level 3	116	27		205	115
Total liabilities, ending balance	(2,694)	(1,999)	(1,512)	(2,694)	(1,999)
Current Period Unrealized Gains (Losses) Still Held Included in Earnings	89	40		415	17
Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income	0	1		17	1
Level 3 | Interest rate contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	(4)	8		0	34
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Earnings	(1)	(8)		(2)	(34)
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	0		0	0
Derivatives, net, Purchases	0	0		0	0
Derivatives, net, Issuances	0	0		0	0
Derivatives, net, Settlements	0	0		0	0
Derivatives, net, Transfers into Level 3	0	0		(3)	0
Derivatives, net, Transfers out of Level 3	0	0		0	0
Derivatives, net, Ending Balance	(5)	0	8	(5)	0
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	(1)	0		(2)	(5)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	0	0		0	0
Level 3 | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance		(1)		(2)	9
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Earnings		0		2	(10)
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income		0		0	0
Derivatives, net, Purchases		0		0	0
Derivatives, net, Issuances		0		0	0
Derivatives, net, Settlements		0		0	0
Derivatives, net, Transfers into Level 3		0		0	0
Derivatives, net, Transfers out of Level 3		0		0	0
Derivatives, net, Ending Balance	0	(1)	(1)	0	(1)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Earnings		0		0	(11)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)		0		0	0
Level 3 | Equity contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	(282)	(13)		46	119
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Earnings	(69)	(91)		(410)	(230)
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	0		0	0
Derivatives, net, Purchases	0	0		0	0
Derivatives, net, Issuances	0	0		0	0
Derivatives, net, Settlements	13	256		(39)	283
Derivatives, net, Transfers into Level 3	(17)	38		5	(30)
Derivatives, net, Transfers out of Level 3	9	0	27	52	(28)
Derivatives, net, Ending Balance	(346)	114	(13)	(346)	114
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	(63)	(2)		(345)	22
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	0	0		0	0
Level 3 | Credit contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	(1)	46		(2)	63
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Earnings	1	(49)		2	(65)
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	0		0	0
Derivatives, net, Purchases	0	0		0	0
Derivatives, net, Issuances	0	0		0	0
Derivatives, net, Settlements	0	1		0	0
Derivatives, net, Transfers into Level 3	0	0		0	0
Derivatives, net, Transfers out of Level 3	0	0		0	0
Derivatives, net, Ending Balance	0	(2)	46	0	(2)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	1	0		2	(2)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	0	0		0	0
Level 3 | Other Contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	(47)	(48)		(33)	(59)
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Earnings	4	3		(27)	0
Derivatives, net, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	0		0	0
Derivatives, net, Purchases	0	0		0	0
Derivatives, net, Issuances	0	0		0	0
Derivatives, net, Settlements	14	6		31	20
Derivatives, net, Transfers into Level 3	0	0		0	0
Derivatives, net, Transfers out of Level 3	0	0		0	0
Derivatives, net, Ending Balance	(29)	(39)	(48)	(29)	(39)
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	0	0		0	0
Derivatives, net, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	0	0		0	0
Asset-backed securities available-for-sale | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total assets, beginning balance	113	126		120	131
Assets, Total Realized/Unrealized Gains (Losses) Included in Earnings	0	0		0	0
Assets, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	(5)	(2)		(9)	(3)
Assets, Purchases	0	0		0	0
Assets, Issuances	0	0		0	0
Assets, Settlements	(1)	(3)		(4)	(7)
Assets, Transfers Into Level 3	0	0		0	0
Assets Transfers out of Level 3	0	0		0	0
Total assets, ending balance	107	121	126	107	121
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	0	0		0	0
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	(5)	(2)		(9)	(3)
Mortgage servicing rights | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total assets, beginning balance	22	12		16	7
Assets, Total Realized/Unrealized Gains (Losses) Included in Earnings	0	1		4	0
Assets, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	0	0		0	0
Assets, Purchases	0	0		0	0
Assets, Issuances	1	1		3	7
Assets, Settlements	0	0		0	0
Assets, Transfers Into Level 3	0	0		0	0
Assets Transfers out of Level 3	0	0		0	0
Total assets, ending balance	23	14	12	23	14
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Earnings	0	1		2	0
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)	0	0		0	0
Derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total assets, ending balance	107	319		107	319
Residential mortgage asset-backed securities | Trading assets, excluding derivatives | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total assets, beginning balance					15
Assets, Total Realized/Unrealized Gains (Losses) Included in Earnings					9
Assets, Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)					0
Assets, Purchases					0
Assets, Issuances					0
Assets, Settlements					0
Assets, Transfers Into Level 3					0
Assets Transfers out of Level 3			24		(24)
Total assets, ending balance		0			0
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Earnings					0
Assets, Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income (Loss)					0
Domestic deposits | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total liabilities, beginning balance	(500)	(593)		(535)	(646)
Total Realized/Unrealized Gains (Losses) Included in Earnings	17	9		62	1
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	1		1	2
Purchases	0	0		0	0
Issuances	0	0		0	0
Settlements	104	58		220	146
Transfers Into Level 3	(26)	0		(156)	(109)
Transfers Out of Level 3	27	9		30	90
Total liabilities, ending balance	(378)	(516)	(593)	(378)	(516)
Current Period Unrealized Gains (Losses) Still Held Included in Earnings	13	6		46	3
Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income	0	1		1	2
Long-term debt | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total liabilities, beginning balance	(2,093)	(919)		(1,853)	(448)
Total Realized/Unrealized Gains (Losses) Included in Earnings	72	33		425	10
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income	0	0		16	(1)
Purchases	0	0		0	0
Issuances	(367)	(660)		(1,025)	(1,201)
Settlements	118	54		318	177
Transfers Into Level 3	(135)	(9)		(372)	(45)
Transfers Out of Level 3	89	18		175	25
Total liabilities, ending balance	(2,316)	(1,483)	$ (919)	(2,316)	(1,483)
Current Period Unrealized Gains (Losses) Still Held Included in Earnings	76	34		369	14
Current Period Unrealized Gains (Losses) Still Held Included in Other Comprehensive Income	$ 0	$ 0		$ 16	$ (1)