Fair Value Measurements - Level 3 Reconciliation (Details) - Recurring Fair Value Measurements - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Excess spread financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	$ 509	$ 768
Changes in fair value included in earnings	4	79
Purchases/additions (1)	0	0
Issuances	0	0
Sales/dispositions (2)	0	0
Repayments	4
Settlements	(18)	(32)
Other changes	0	0
Balance - end of period	491	815
Mortgage servicing rights financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	19	10
Changes in fair value included in earnings	2	20
Purchases/additions (1)	0	0
Issuances	0	0
Sales/dispositions (2)	0	0
Repayments	0
Settlements	0	0
Other changes	0	0
Balance - end of period	21	30
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	6,654	4,223
Changes in fair value included in earnings	(230)	563
Purchases/additions (1)	102	1,015
Issuances	54	200
Sales/dispositions (2)	(15)	(4)
Repayments	0
Settlements	0	0
Other changes	1	9
Balance - end of period	6,566	6,006
Equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	45	54
Changes in fair value included in earnings	(3)	0
Purchases/additions (1)	0	0
Issuances	0	0
Sales/dispositions (2)	0	0
Repayments	0
Settlements	0	0
Other changes	0	0
Balance - end of period	42	54
IRLCs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	22	134
Changes in fair value included in earnings	11	(62)
Purchases/additions (1)	0	0
Issuances	0	0
Sales/dispositions (2)	0	0
Repayments	0
Settlements	0	0
Other changes	0	0
Balance - end of period	33	$ 72
Mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	74
Changes in fair value included in earnings	1
Purchases/additions (1)	28
Issuances	0
Sales/dispositions (2)	(31)
Repayments	1
Settlements	0
Other changes	0
Balance - end of period	$ 71

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Other Fair Value Changes

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Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Repayments

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Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Repayments

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sales of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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