Allowance for Credit Losses - Schedule of Gross Charge-Offs by Year of Origination - Prior Year (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
2025			$ 6	$ 6
2024			1	3
2023			32	2
2022			14	14
2021			5	21
Prior to 2021			19	32
Revolving Loans			9	6
Total Charge-offs	$ 41	$ 43	86	84
Commercial \| Commercial, Financial, and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
2025			2	3
2024			0	3
2023			32	1
2022			13	7
2021			4	19
Prior to 2021			11	26
Revolving Loans			6	3
Total Charge-offs	32	28	68	62
Commercial \| CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
2025			0	0
2024			0	0
2023			0	0
2022			0	5
2021			1	0
Prior to 2021			6	5
Revolving Loans			0	0
Total Charge-offs	3	7	7	10
Consumer \| Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2025			0	0
2024			0	0
2023			0	1
2022			1	1
2021			0	0
Prior to 2021			1	0
Revolving Loans			0	0
Total Charge-offs	1	2	2	2
Consumer \| Credit card and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2025			4	3
2024			1	0
2023			0	0
2022			0	1
2021			0	2
Prior to 2021			1	1
Revolving Loans			3	3
Total Charge-offs	$ 5	$ 6	$ 9	$ 10

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Paragraph 2
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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount, excluding accrued interest, of writeoff of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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