Fair Value Measurements - Schedule of Change in Fair Values of Level 3 Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	$ (2)	$ 2
Gains (Losses) Included in Other Comprehensive Income	0	0
Gains (Losses) Included in Earnings	(4)	6
Purchases	1	18
Sales	0	(1)
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	2	(8)
Transfers out of Level 3	3	(4)
End of Period Balance	0	13
Unrealized Gains (Losses) Included in Earnings	0	0
Credit
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	0	(2)
Gains (Losses) Included in Other Comprehensive Income	0	0
Gains (Losses) Included in Earnings	0	1
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	0	(1)
Unrealized Gains (Losses) Included in Earnings	0	0
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	2	0
Gains (Losses) Included in Other Comprehensive Income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	(1)	1
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	1	1
Unrealized Gains (Losses) Included in Earnings	0	0
Loans, net of unearned income (residential)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	9	9
Gains (Losses) Included in Other Comprehensive Income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	9	9
Unrealized Gains (Losses) Included in Earnings	0	0
Other investments
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	2	2
Gains (Losses) Included in Other Comprehensive Income	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	2	2
Unrealized Gains (Losses) Included in Earnings	$ 0	0
Other investments \| Principal investments, Direct
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance		1
Gains (Losses) Included in Other Comprehensive Income		0
Gains (Losses) Included in Earnings		0
Purchases		0
Sales		0
Settlements		0
Transfers Other		0
Transfers into Level 3		0
Transfers out of Level 3		0
End of Period Balance		1
Unrealized Gains (Losses) Included in Earnings		$ 0

Fair value measurement with unobservable inputs reconciliation recurring basis asset and liabilities value.

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- Definition

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Other Transfers

+ References

No definition available.

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of purchases, (sales), issuances and (settlements) 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.

+ References

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- Definition

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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- Definition

Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

+ References

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- Definition

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

+ References

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- Definition

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

+ References

No definition available.

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