Derivative Instruments and Hedging Activities - Hedged Items in Fair Value Hedging Relationship (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Hedged Items In Fair Value Hedging Relationship [Line Items]
Total Assets	$ (19)	$ 29
Discontinued Hedging Relationships, Assets	3,400	3,700
Designated hedged items	2,400	2,500
Balance Sheet Location [Axis]: us-gaap:DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Assets	9,616	9,424
Total Assets	(82)	79
Discontinued Hedging Relationships, Assets	41	44
Balance Sheet Location [Axis]: us-gaap:InterestBearingDepositLiabilities
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(5,776)	(6,702)
Total Liabilities	49	17
Discontinued Hedging Relationships, Liabilities	0	0
Balance Sheet Location [Axis]: us-gaap:SecuredDebt
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(6,761)	(10,236)
Total Liabilities	172	136
Discontinued Hedging Relationships, Liabilities	0	0
Balance Sheet Location [Axis]: us-gaap:UnsecuredDebt
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(33,657)	(34,599)
Total Liabilities	763	335
Discontinued Hedging Relationships, Liabilities	$ (66)	$ (115)

Carry amount of assets hedged in fair value hedging relationship

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- Definition

The carry amount of liabilities in fair value hedging relationship

+ References

No definition available.

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- Definition

[Line Items] for Table shows the carrying amount and associated cumulative basis adjustment related to the application of hedge accounting that is included in the carrying amount of hedged assets and liabilities in fair value hedging relationships.

+ References

No definition available.

+ Details

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, remaining after discontinued hedge. Excludes cumulative basis adjustment related to foreign exchange risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EE

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk. Excludes cumulative basis adjustment related to foreign exchange risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EE

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk, remaining after discontinued hedge. Excludes cumulative basis adjustment related to foreign exchange risk.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk. Excludes cumulative basis adjustment related to foreign exchange risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EE

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- Definition

Amortized cost of closed portfolio of financial asset used to designate hedging relationship in which hedged item is expected to be outstanding for designated hedged period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EEE
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4EEE

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-Topic 815
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-Paragraph 181
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

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