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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	$ 1,664	$ 1,389	$ 1,673	$ 1,065
Included in earnings	(7)	19	(75)	140
Purchases/originations	26	110	56	294
Settlements	3	5	27	18
Transfers into Level 3	0	1	5	7
Balance, end of period	1,686	1,524	1,686	1,524
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	8	52	(57)	238
Derivative assets	2,925		2,925		$ 3,171
Derivative liabilities	3,424		3,424		$ 3,951
Unrealized gains or losses included in other comprehensive income for instruments still held	0	0	0	0
Interest rate contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Derivative assets	10	17	10	17
Derivative liabilities	8	9	8	9
Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	1,725	1,444	1,746	1,121
Included in earnings	13	32	(40)	169
Purchases/originations	26	106	58	292
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Balance, end of period	1,764	1,582	1,764	1,582
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	33	65	(3)	267
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	3	(2)	(1)	4
Included in earnings	11	12	25	13
Purchases/originations	0	4	(2)	2
Settlements	(12)	(6)	(20)	(11)
Transfers into Level 3	0	0	0	0
Balance, end of period	2	8	2	8
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	6	12	6	13
Equity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	(192)	(198)	(195)	(214)
Included in earnings	(30)	(18)	(61)	(29)
Purchases/originations	0	0	0	0
Settlements	18	17	52	44
Transfers into Level 3	0	0	0	0
Balance, end of period	(204)	(199)	(204)	(199)
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	(30)	(18)	(61)	(29)
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	128	145	123	154
Included in earnings	(1)	(7)	1	(13)
Purchases/originations	0	0	0	0
Settlements	(3)	(6)	(5)	(15)
Transfers into Level 3	0	1	5	7
Balance, end of period	124	133	124	133
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	$ (1)	$ (7)	$ 1	$ (13)