Fair Value Measurements - Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation
Derivative assets	$ 4,336		$ 4,336		$ 2,896
Derivative liabilities	5,146		5,146		$ 2,013
Unrealized gains or losses included in other comprehensive income for instruments still held	0	$ 0	0	$ 0
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	1,524	787	1,065	669
Total (losses) gains (realized/unrealized) included in earnings	19	(17)	159	(27)
Purchases/originations	101	169	395	380
Settlements	29	(50)	47	(153)
Transfers into Level 3	3	18	10	38
Balance, end of period	1,676	907	1,676	907
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	54	27	273	37
Interest rate contracts | Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation
Derivative assets	7	27	7	27
Derivative liabilities	14	8	14	8
Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	1,582	818	1,121	656
Total (losses) gains (realized/unrealized) included in earnings	48	(44)	217	(95)
Purchases/originations	102	169	394	382
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Balance, end of period	1,732	943	1,732	943
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	80	19	338	77
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	8	31	4	53
Total (losses) gains (realized/unrealized) included in earnings	(5)	44	8	136
Purchases/originations	(1)	0	1	(2)
Settlements	(9)	(56)	(20)	(168)
Transfers into Level 3	0	0	0	0
Balance, end of period	(7)	19	(7)	19
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	(2)	25	1	28
Equity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	(199)	(213)	(214)	(201)
Total (losses) gains (realized/unrealized) included in earnings	(17)	(17)	(46)	(67)
Purchases/originations	0	0	0	0
Settlements	42	19	86	57
Transfers into Level 3	0	0	0	0
Balance, end of period	(174)	(211)	(174)	(211)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	(17)	(17)	(46)	(67)
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	133	151	154	161
Total (losses) gains (realized/unrealized) included in earnings	(7)	0	(20)	(1)
Purchases/originations	0	0	0	0
Settlements	(4)	(13)	(19)	(42)
Transfers into Level 3	3	18	10	38
Balance, end of period	125	156	125	156
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	$ (7)	$ 0	$ (20)	$ (1)