Fair Value Measurements - Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation
Derivative assets	$ 2,908	$ 2,919
Derivative liabilities	2,013	1,072
Unrealized gains or losses included in other comprehensive income for instruments still held	0	0
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	669	1,023	$ 991
Included in earnings	(74)	(393)	(339)
Purchases/originations	601	232	428
Settlements	(180)	(242)	(93)
Transfers into Level 3	49	49	36
Balance, end of period	1,065	669	1,023
The amount of total (losses) gains for the period included in earnings attributable to the change in unrealized gains or losses relating to instruments still held	5	(269)	(338)
Interest Rate Contract \| Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation
Derivative assets	12	61	18
Derivative liabilities	8	8	8
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	161	183	179
Included in earnings	(2)	3	(1)
Purchases/originations	0	0	0
Settlements	(54)	(74)	(31)
Transfers into Level 3	49	49	36
Balance, end of period	154	161	183
The amount of total (losses) gains for the period included in earnings attributable to the change in unrealized gains or losses relating to instruments still held	(2)	3	(1)
Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	656	993	938
Included in earnings	(139)	(565)	(376)
Purchases/originations	604	228	431
Settlements	0	0	0
Transfers into Level 3	0	0	0
Balance, end of period	1,121	656	993
The amount of total (losses) gains for the period included in earnings attributable to the change in unrealized gains or losses relating to instruments still held	78	(227)	(250)
Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	53	10	(1)
Included in earnings	153	272	145
Purchases/originations	(3)	4	(3)
Settlements	(199)	(233)	(131)
Transfers into Level 3	0	0	0
Balance, end of period	4	53	10
The amount of total (losses) gains for the period included in earnings attributable to the change in unrealized gains or losses relating to instruments still held	15	58	20
Equity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	(201)	(163)	(125)
Included in earnings	(86)	(103)	(107)
Purchases/originations	0	0	0
Settlements	73	65	69
Transfers into Level 3	0	0	0
Balance, end of period	(214)	(201)	(163)
The amount of total (losses) gains for the period included in earnings attributable to the change in unrealized gains or losses relating to instruments still held	$ (86)	$ (103)	$ (107)

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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