Derivative Financial Instruments - Derivative Instruments (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional	$ 27,636	$ 9,421
Fair Value	475	170
Gains/(Losses)	322	107
Assets \| Loan sale commitments
Derivatives, Fair Value [Line Items]
Outstanding Notional	1,908	1,508
Fair Value	75	35
Gains/(Losses)	43	9
Assets \| IRLCs
Derivatives, Fair Value [Line Items]
Outstanding Notional	10,967	4,964
Fair Value	414	144
Gains/(Losses)	279	84
Assets \| LPCs
Derivatives, Fair Value [Line Items]
Outstanding Notional	5,217	1,397
Fair Value	38	18
Gains/(Losses)	26	17
Assets \| Forward MBS trades
Derivatives, Fair Value [Line Items]
Outstanding Notional	11,452	3,054
Fair Value	23	8
Gains/(Losses)	17	6
Assets \| Eurodollar futures
Derivatives, Fair Value [Line Items]
Outstanding Notional		6
Fair Value		0
Gains/(Losses)		0
Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional	16,574	6,237
Derivative financial instruments	44	19
Gains/(Losses)	29	(5)
Liabilities \| IRLCs
Derivatives, Fair Value [Line Items]
Outstanding Notional	2	15
Derivative financial instruments	0	0
Gains/(Losses)	0	0
Liabilities \| LPCs
Derivatives, Fair Value [Line Items]
Outstanding Notional	598	547
Derivative financial instruments	2	3
Gains/(Losses)	(1)	3
Liabilities \| Forward MBS trades
Derivatives, Fair Value [Line Items]
Outstanding Notional	15,974	5,667
Derivative financial instruments	42	16
Gains/(Losses)	$ 30	(8)
Liabilities \| Eurodollar futures
Derivatives, Fair Value [Line Items]
Outstanding Notional		8
Derivative financial instruments		0
Gains/(Losses)		$ 0

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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Fair value, before 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 elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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

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No definition available.

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