LOANS AND LEASES - Schedule of Loans Disaggregated by Year of Origination and by Risk Rating (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025	Sep. 30, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 157,190	$ 147,930	$ 144,758
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	19,764	23,821
Term loans by origination year, year two	17,994	17,214
Term loans by origination year, year three	12,965	11,387
Term loans by origination year, year four	8,063	9,341
Term loans by origination year, year five	7,234	6,021
Prior year	11,781	8,744
Revolving	52,795	44,061
Revolving Converted to Term Loans	180	145
Total loans and leases	130,776	120,734
Commercial \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	18,748	22,286
Term loans by origination year, year two	16,605	16,013
Term loans by origination year, year three	11,984	10,351
Term loans by origination year, year four	7,339	8,251
Term loans by origination year, year five	6,362	5,332
Prior year	10,978	8,124
Revolving	52,092	43,207
Revolving Converted to Term Loans	172	137
Total loans and leases	124,280	113,701
Commercial \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	298	470
Term loans by origination year, year two	452	395
Term loans by origination year, year three	360	302
Term loans by origination year, year four	201	219
Term loans by origination year, year five	274	169
Prior year	167	118
Revolving	174	202
Revolving Converted to Term Loans	0	0
Total loans and leases	1,926	1,875
Commercial \| Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	652	1,005
Term loans by origination year, year two	897	764
Term loans by origination year, year three	603	681
Term loans by origination year, year four	482	813
Term loans by origination year, year five	542	509
Prior year	592	480
Revolving	355	475
Revolving Converted to Term Loans	8	8
Total loans and leases	4,131	4,735
Commercial \| Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	66	60
Term loans by origination year, year two	40	42
Term loans by origination year, year three	18	53
Term loans by origination year, year four	41	58
Term loans by origination year, year five	56	11
Prior year	44	22
Revolving	20	34
Revolving Converted to Term Loans	0	0
Total loans and leases	285	280
Commercial \| Ungraded
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	154	143
Revolving Converted to Term Loans	0	0
Total loans and leases	154	143
Commercial \| Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	12,503	14,166
Term loans by origination year, year two	9,733	8,490
Term loans by origination year, year three	5,706	3,907
Term loans by origination year, year four	2,732	3,570
Term loans by origination year, year five	2,203	1,928
Prior year	2,561	1,664
Revolving	13,113	10,915
Revolving Converted to Term Loans	133	81
Total loans and leases	48,684	44,721
Commercial \| Commercial and industrial \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	12,042	13,484
Term loans by origination year, year two	9,117	7,906
Term loans by origination year, year three	5,071	3,552
Term loans by origination year, year four	2,452	2,963
Term loans by origination year, year five	1,731	1,428
Prior year	2,195	1,539
Revolving	12,503	10,143
Revolving Converted to Term Loans	126	76
Total loans and leases	45,237	41,091
Commercial \| Commercial and industrial \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	167	213
Term loans by origination year, year two	197	264
Term loans by origination year, year three	280	113
Term loans by origination year, year four	92	97
Term loans by origination year, year five	110	143
Prior year	100	60
Revolving	149	181
Revolving Converted to Term Loans	0	0
Total loans and leases	1,095	1,071
Commercial \| Commercial and industrial \| Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	238	451
Term loans by origination year, year two	392	296
Term loans by origination year, year three	341	215
Term loans by origination year, year four	168	475
Term loans by origination year, year five	323	347
Prior year	237	65
Revolving	289	416
Revolving Converted to Term Loans	7	5
Total loans and leases	1,995	2,270
Commercial \| Commercial and industrial \| Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	56	18
Term loans by origination year, year two	27	24
Term loans by origination year, year three	14	27
Term loans by origination year, year four	20	35
Term loans by origination year, year five	39	10
Prior year	29	0
Revolving	18	32
Revolving Converted to Term Loans	0	0
Total loans and leases	203	146
Commercial \| Commercial and industrial \| Ungraded
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	154	143
Revolving Converted to Term Loans	0	0
Total loans and leases	154	143
Commercial \| Capital call lines
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	38,108	31,758
Revolving Converted to Term Loans	18	33
Total loans and leases	38,126	31,791
Commercial \| Capital call lines \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	38,108	31,758
Revolving Converted to Term Loans	18	33
Total loans and leases	38,126	31,791
Commercial \| Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	2,384	2,883
Term loans by origination year, year two	2,742	2,832
Term loans by origination year, year three	2,660	2,364
Term loans by origination year, year four	2,086	2,687
Term loans by origination year, year five	2,475	2,402
Prior year	5,675	4,203
Revolving	295	258
Revolving Converted to Term Loans	29	31
Total loans and leases	18,346	17,660
Commercial \| Owner occupied commercial mortgage \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	2,339	2,816
Term loans by origination year, year two	2,659	2,739
Term loans by origination year, year three	2,533	2,177
Term loans by origination year, year four	1,911	2,430
Term loans by origination year, year five	2,242	2,290
Prior year	5,392	3,954
Revolving	281	248
Revolving Converted to Term Loans	28	28
Total loans and leases	17,385	16,682
Commercial \| Owner occupied commercial mortgage \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	20	26
Term loans by origination year, year two	25	34
Term loans by origination year, year three	32	49
Term loans by origination year, year four	35	78
Term loans by origination year, year five	104	24
Prior year	55	27
Revolving	3	2
Revolving Converted to Term Loans	0	0
Total loans and leases	274	240
Commercial \| Owner occupied commercial mortgage \| Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	25	41
Term loans by origination year, year two	58	55
Term loans by origination year, year three	95	128
Term loans by origination year, year four	132	179
Term loans by origination year, year five	129	88
Prior year	226	222
Revolving	11	8
Revolving Converted to Term Loans	1	3
Total loans and leases	677	724
Commercial \| Owner occupied commercial mortgage \| Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	4
Term loans by origination year, year three	0	10
Term loans by origination year, year four	8	0
Term loans by origination year, year five	0	0
Prior year	2	0
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	10	14
Commercial \| Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	735	1,127
Term loans by origination year, year two	950	901
Term loans by origination year, year three	423	244
Term loans by origination year, year four	70	105
Term loans by origination year, year five	46	4
Prior year	0	0
Revolving	358	397
Revolving Converted to Term Loans	0	0
Total loans and leases	2,582	2,778
Commercial \| Investor dependent \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	682	981
Term loans by origination year, year two	719	648
Term loans by origination year, year three	246	110
Term loans by origination year, year four	29	67
Term loans by origination year, year five	46	0
Prior year	0	0
Revolving	280	326
Revolving Converted to Term Loans	0	0
Total loans and leases	2,002	2,132
Commercial \| Investor dependent \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	20	29
Term loans by origination year, year two	84	78
Term loans by origination year, year three	44	1
Term loans by origination year, year four	2	19
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	22	19
Revolving Converted to Term Loans	0	0
Total loans and leases	172	146
Commercial \| Investor dependent \| Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	26	104
Term loans by origination year, year two	138	164
Term loans by origination year, year three	129	117
Term loans by origination year, year four	34	14
Term loans by origination year, year five	0	4
Prior year	0	0
Revolving	54	50
Revolving Converted to Term Loans	0	0
Total loans and leases	381	453
Commercial \| Investor dependent \| Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	7	13
Term loans by origination year, year two	9	11
Term loans by origination year, year three	4	16
Term loans by origination year, year four	5	5
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	2	2
Revolving Converted to Term Loans	0	0
Total loans and leases	27	47
Commercial \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	4,142	5,645
Term loans by origination year, year two	4,569	4,991
Term loans by origination year, year three	4,176	4,872
Term loans by origination year, year four	3,175	2,979
Term loans by origination year, year five	2,510	1,687
Prior year	3,545	2,877
Revolving	921	733
Revolving Converted to Term Loans	0	0
Total loans and leases	23,038	23,784
Commercial \| Commercial real estate \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	3,685	5,005
Term loans by origination year, year two	4,110	4,720
Term loans by origination year, year three	4,134	4,512
Term loans by origination year, year four	2,947	2,791
Term loans by origination year, year five	2,343	1,614
Prior year	3,391	2,631
Revolving	920	732
Revolving Converted to Term Loans	0	0
Total loans and leases	21,530	22,005
Commercial \| Commercial real estate \| Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	91	202
Term loans by origination year, year two	146	19
Term loans by origination year, year three	4	139
Term loans by origination year, year four	72	25
Term loans by origination year, year five	60	2
Prior year	12	31
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	385	418
Commercial \| Commercial real estate \| Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	363	409
Term loans by origination year, year two	309	249
Term loans by origination year, year three	38	221
Term loans by origination year, year four	148	145
Term loans by origination year, year five	90	70
Prior year	129	193
Revolving	1	1
Revolving Converted to Term Loans	0	0
Total loans and leases	1,078	1,288
Commercial \| Commercial real estate \| Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	3	29
Term loans by origination year, year two	4	3
Term loans by origination year, year three	0	0
Term loans by origination year, year four	8	18
Term loans by origination year, year five	17	1
Prior year	13	22
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	45	73
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	1,870	2,290
Term loans by origination year, year two	1,963	2,131
Term loans by origination year, year three	1,853	2,820
Term loans by origination year, year four	2,428	5,049
Term loans by origination year, year five	4,658	4,852
Prior year	10,319	6,549
Revolving	3,140	3,351
Revolving Converted to Term Loans	183	154
Total loans and leases	26,414	27,196
Consumer \| Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	1,447	1,605
Term loans by origination year, year two	1,505	1,619
Term loans by origination year, year three	1,511	2,533
Term loans by origination year, year four	2,252	4,834
Term loans by origination year, year five	4,538	4,757
Prior year	10,256	6,509
Revolving	7	4
Revolving Converted to Term Loans	0	0
Total loans and leases	21,516	21,861
Consumer \| Residential mortgage \| Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	1,444	1,601
Term loans by origination year, year two	1,495	1,609
Term loans by origination year, year three	1,500	2,512
Term loans by origination year, year four	2,220	4,783
Term loans by origination year, year five	4,495	4,715
Prior year	10,066	6,295
Revolving	7	2
Revolving Converted to Term Loans	0	0
Total loans and leases	21,227	21,517
Consumer \| Residential mortgage \| 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	2	3
Term loans by origination year, year two	5	4
Term loans by origination year, year three	4	12
Term loans by origination year, year four	18	32
Term loans by origination year, year five	17	32
Prior year	74	94
Revolving	0	2
Revolving Converted to Term Loans	0	0
Total loans and leases	120	179
Consumer \| Residential mortgage \| 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	1	0
Term loans by origination year, year two	0	1
Term loans by origination year, year three	2	3
Term loans by origination year, year four	1	9
Term loans by origination year, year five	6	3
Prior year	30	38
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	40	54
Consumer \| Residential mortgage \| 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	1
Term loans by origination year, year two	5	5
Term loans by origination year, year three	5	6
Term loans by origination year, year four	13	10
Term loans by origination year, year five	20	7
Prior year	86	82
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	129	111
Consumer \| Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	2,670	2,709
Revolving Converted to Term Loans	183	154
Total loans and leases	2,853	2,863
Consumer \| Revolving mortgage \| Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	2,654	2,686
Revolving Converted to Term Loans	150	125
Total loans and leases	2,804	2,811
Consumer \| Revolving mortgage \| 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	13	20
Revolving Converted to Term Loans	10	9
Total loans and leases	23	29
Consumer \| Revolving mortgage \| 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	0	0
Revolving Converted to Term Loans	7	6
Total loans and leases	7	6
Consumer \| Revolving mortgage \| 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	0
Term loans by origination year, year three	0	0
Term loans by origination year, year four	0	0
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	3	3
Revolving Converted to Term Loans	16	14
Total loans and leases	19	17
Consumer \| Auto
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	292	507
Term loans by origination year, year two	356	411
Term loans by origination year, year three	285	222
Term loans by origination year, year four	143	162
Term loans by origination year, year five	97	80
Prior year	51	34
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	1,224	1,416
Consumer \| Auto \| Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	291	504
Term loans by origination year, year two	352	405
Term loans by origination year, year three	279	217
Term loans by origination year, year four	139	157
Term loans by origination year, year five	94	77
Prior year	50	33
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	1,205	1,393
Consumer \| Auto \| 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	1	3
Term loans by origination year, year two	3	4
Term loans by origination year, year three	4	3
Term loans by origination year, year four	2	3
Term loans by origination year, year five	2	2
Prior year	1	1
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	13	16
Consumer \| Auto \| 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	1	1
Term loans by origination year, year three	1	1
Term loans by origination year, year four	1	1
Term loans by origination year, year five	1	1
Prior year	0	0
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	4	4
Consumer \| Auto \| 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	0	0
Term loans by origination year, year two	0	1
Term loans by origination year, year three	1	1
Term loans by origination year, year four	1	1
Term loans by origination year, year five	0	0
Prior year	0	0
Revolving	0	0
Revolving Converted to Term Loans	0	0
Total loans and leases	2	3
Consumer \| Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loans by origination year, year one	131	178

LOANS AND LEASES - Schedule of Loans Disaggregated by Year of Origination and by Risk Rating (Details) - USD ($)
$ in Millions

Sep. 30, 2026

Dec. 31, 2025

Sep. 30, 2025

Accounts, Notes, Loans and Financing Receivable [Line Items]

Total loans and leases

$ 157,190

$ 147,930

$ 144,758

Commercial

Accounts, Notes, Loans and Financing Receivable [Line Items]

Term loans by origination year, year one