LOANS, LEASES, AND ALLOWANCE FOR CREDIT LOSSES (Summary of Nonaccrual Loans) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	$ 99	$ 91
Amortized cost basis with allowance	264	131
Nonaccrual loans that are current	363	222
Related allowance	41	43
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	45	23
Amortized cost basis with allowance	170	81
Nonaccrual loans that are current	215	104
Related allowance	28	32
Commercial \| Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	27	11
Amortized cost basis with allowance	146	71
Nonaccrual loans that are current	173	82
Related allowance	25	30
Commercial \| Leasing
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	0
Amortized cost basis with allowance	2	2
Nonaccrual loans that are current	2	2
Related allowance	0	1
Commercial \| Owner-occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	13	12
Amortized cost basis with allowance	16	8
Nonaccrual loans that are current	29	20
Related allowance	1	1
Commercial \| Municipal
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	5
Amortized cost basis with allowance	6
Nonaccrual loans that are current	11
Related allowance	2
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	38	59
Amortized cost basis with allowance	31	2
Nonaccrual loans that are current	69	61
Related allowance	2	1
Commercial real estate \| Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0	22
Amortized cost basis with allowance	2	0
Nonaccrual loans that are current	2	22
Related allowance	0	0
Commercial real estate \| Term
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	38	37
Amortized cost basis with allowance	29	2
Nonaccrual loans that are current	67	39
Related allowance	2	1
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	16	9
Amortized cost basis with allowance	63	48
Nonaccrual loans that are current	79	57
Related allowance	11	10
Consumer \| Home equity credit line
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	4	1
Amortized cost basis with allowance	26	16
Nonaccrual loans that are current	30	17
Related allowance	6	5
Consumer \| 1-4 family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	12	8
Amortized cost basis with allowance	35	32
Nonaccrual loans that are current	47	40
Related allowance	4	$ 5
Consumer \| Bankcard and other revolving plans
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0
Amortized cost basis with allowance	1
Nonaccrual loans that are current	1
Related allowance	1
Consumer \| Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost basis with no allowance	0
Amortized cost basis with allowance	1
Nonaccrual loans that are current	1
Related allowance	$ 0

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/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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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
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
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-Section 50
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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