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LOANS, LEASES, AND ALLOWANCE FOR CREDIT LOSSES (Summary of Nonaccrual Loans) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	$ 75	$ 112
Amortized cost basis with allowance	244	185
Nonaccrual loans that are current	319	297
Related allowance	40	37
Commercial:
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	63	68
Amortized cost basis with allowance	90	90
Nonaccrual loans that are current	153	158
Related allowance	25	23
Commercial: | Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	50	45
Amortized cost basis with allowance	57	69
Nonaccrual loans that are current	107	114
Related allowance	22	19
Commercial: | Owner-occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	13	18
Amortized cost basis with allowance	27	13
Nonaccrual loans that are current	40	31
Related allowance	2	1
Commercial: | Municipal
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	5
Amortized cost basis with allowance	2	6
Nonaccrual loans that are current	2	11
Related allowance	0	2
Commercial: | Leasing
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	0
Amortized cost basis with allowance	4	2
Nonaccrual loans that are current	4	2
Related allowance	1	1
Commercial real estate:
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	1	27
Amortized cost basis with allowance	69	32
Nonaccrual loans that are current	70	59
Related allowance	3	4
Commercial real estate: | Term
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	1	27
Amortized cost basis with allowance	69	32
Nonaccrual loans that are current	70	59
Related allowance	3	4
Consumer:
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	11	17
Amortized cost basis with allowance	85	63
Nonaccrual loans that are current	96	80
Related allowance	12	10
Consumer: | 1-4 family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	11	12
Amortized cost basis with allowance	52	37
Nonaccrual loans that are current	63	49
Related allowance	4	4
Consumer: | Home equity credit line
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	5
Amortized cost basis with allowance	32	25
Nonaccrual loans that are current	32	30
Related allowance	7	5
Consumer: | Bankcard and other revolving plans
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	0
Amortized cost basis with allowance	1	1
Nonaccrual loans that are current	1	1
Related allowance	$ 1	$ 1

X

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 13
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 13
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Section 50
-Paragraph 13
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
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-Paragraph c
-Publisher SEC

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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

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

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