Fair Value Measurements - Level 3 Reconciliation (Details) - Recurring Fair Value Measurements - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Excess spread financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	$ 437	$ 509
Changes in fair value included in earnings	0	4
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(2)	0
Repayments	0	(4)
Settlements	(17)	(18)
Other changes	0	0
Balance - end of period	420	491
Mortgage servicing rights financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	29	19
Changes in fair value included in earnings	6	2
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(2)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of period	35	21
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	9,090	6,654
Changes in fair value included in earnings	10	(230)
Purchases/additions(1)	663	102
Issuances	64	54
Sales/dispositions(2)	(42)	(15)
Repayments	0	0
Settlements	0	0
Other changes	(11)	(1)
Balance - end of period	9,796	6,566
Mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	81	74
Changes in fair value included in earnings	(2)	1
Purchases/additions(1)	28	28
Issuances	0	0
Sales/dispositions(2)	(22)	(31)
Repayments	(2)	(1)
Settlements	0	0
Other changes	1	0
Balance - end of period	82	71
Equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	8	45
Changes in fair value included in earnings	0	(3)
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(2)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of period	8	42
IRLCs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of period	21	22
Changes in fair value included in earnings	6	11
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(2)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of period	$ 27	$ 33

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, Other Fair Value Changes

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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
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-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
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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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