Fair Value Measurements - Reconciliation of Level 3 (Details) - Recurring Fair Value Measurements - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Excess spread financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	$ 509	$ 768
Changes in fair value included in earnings	8	133
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(1)	0	0
Repayments	(9)	(293)
Settlements	(71)	(99)
Other changes	0	0
Balance - end of year	437	509
Mortgage servicing rights financing
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	19	10
Changes in fair value included in earnings	10	9
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(1)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of year	29	19
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	6,654	4,223
Changes in fair value included in earnings	(483)	549
Purchases/additions(1)	3,189	1,595
Issuances	273	554
Sales/dispositions(1)	(573)	(294)
Repayments	0	0
Settlements	0	0
Other changes	30	(27)
Balance - end of year	9,090	6,654
Mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	74	76
Changes in fair value included in earnings	18	(3)
Purchases/additions(1)	180	130
Issuances	0	0
Sales/dispositions(1)	(189)	(124)
Repayments	(6)	(2)
Settlements	0	0
Other changes	4	(3)
Balance - end of year	81	74
Equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	45	54
Changes in fair value included in earnings	(37)	(9)
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(1)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of year	8	45
IRLCs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - beginning of year	22	134
Changes in fair value included in earnings	(1)	(112)
Purchases/additions(1)	0	0
Issuances	0	0
Sales/dispositions(1)	0	0
Repayments	0	0
Settlements	0	0
Other changes	0	0
Balance - end of year	$ 21	$ 22

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

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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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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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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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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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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 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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