Derivative Financial Instruments - Outstanding Balances (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Assets
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	$ 9,293	$ 21,438
Derivative asset, fair value	144	489
Gains/(Losses)	(338)	336
Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	5,670	25,498
Derivative liability, fair value	16	157
Gains/(Losses)	(87)	142
Loan sale commitments \| Assets
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	1,051	2,710
Derivative asset, fair value	25	102
Gains/(Losses)	(77)	70
IRLCs \| Assets
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	5,237	10,179
Derivative asset, fair value	134	414
Gains/(Losses)	(280)	279
IRLCs \| Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	10	2
Derivative liability, fair value	0	0
Gains/(Losses)	0	0
LPCs \| Assets
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	487	5,406
Derivative asset, fair value	3	38
Gains/(Losses)	(35)	26
LPCs \| Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	646	280
Derivative liability, fair value	2	1
Gains/(Losses)	1	(2)
Forward MBS trades \| Assets
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	3,569	5,853
Derivative asset, fair value	7	37
Gains/(Losses)	(23)	31
Forward MBS trades \| Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	4,091	25,156
Derivative liability, fair value	8	156
Gains/(Losses)	(94)	144
Swap futures \| Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	923	60
Derivative liability, fair value	6	0
Gains/(Losses)	$ 6	$ 0

Nominal or face amount used to calculate payments on the derivative asset.

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