LOANS AND LEASES - Origination Year (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 3,686	$ 6,587
Fiscal year before current fiscal year	6,569	4,518
Two years before current fiscal year	4,278	3,256
Three years before current fiscal year	3,041	1,952
Four years before current fiscal year	1,761	1,579
Prior	5,394	4,130
Revolving Loans Amortized Cost Basis	3,315	2,946
Total Loans and Leases	28,044	24,968
Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	27,881	24,815
Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	163	153
Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,908	3,786
Fiscal year before current fiscal year	3,643	2,779
Two years before current fiscal year	2,659	2,484
Three years before current fiscal year	2,334	1,486
Four years before current fiscal year	1,386	1,200
Prior	3,828	2,858
Revolving Loans Amortized Cost Basis	2,233	1,872
Total Loans and Leases	17,991	16,465
Total commercial loans and leases | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	17,914	16,385
Total commercial loans and leases | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	77	80
Total commercial loans and leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	900	1,893
Fiscal year before current fiscal year	2,170	1,818
Two years before current fiscal year	1,777	1,620
Three years before current fiscal year	1,542	980
Four years before current fiscal year	929	895
Prior	3,186	2,498
Revolving Loans Amortized Cost Basis	283	195
Total Loans and Leases	10,787	9,899
Total commercial loans and leases | Commercial real estate | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	10,730	9,840
Total commercial loans and leases | Commercial real estate | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	57	59
Total commercial loans and leases | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	897	1,878
Fiscal year before current fiscal year	2,126	1,782
Two years before current fiscal year	1,743	1,503
Three years before current fiscal year	1,422	830
Four years before current fiscal year	785	743
Prior	2,738	2,171
Revolving Loans Amortized Cost Basis	252	183
Total Loans and Leases	9,963	9,090
Total commercial loans and leases | Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1	15
Fiscal year before current fiscal year	33	21
Two years before current fiscal year	21	89
Three years before current fiscal year	85	105
Four years before current fiscal year	99	107
Prior	259	175
Revolving Loans Amortized Cost Basis	3	9
Total Loans and Leases	501	521
Total commercial loans and leases | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2	0
Fiscal year before current fiscal year	11	15
Two years before current fiscal year	13	28
Three years before current fiscal year	35	45
Four years before current fiscal year	45	45
Prior	189	152
Revolving Loans Amortized Cost Basis	28	3
Total Loans and Leases	323	288
Total commercial loans and leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	861	1,672
Fiscal year before current fiscal year	1,315	849
Two years before current fiscal year	791	763
Three years before current fiscal year	707	450
Four years before current fiscal year	410	263
Prior	593	355
Revolving Loans Amortized Cost Basis	1,887	1,625
Total Loans and Leases	6,564	5,977
Total commercial loans and leases | Commercial and industrial | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	6,547	5,958
Total commercial loans and leases | Commercial and industrial | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	17	19
Total commercial loans and leases | Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	858	1,663
Fiscal year before current fiscal year	1,294	833
Two years before current fiscal year	760	731
Three years before current fiscal year	682	386
Four years before current fiscal year	356	184
Prior	434	296
Revolving Loans Amortized Cost Basis	1,798	1,509
Total Loans and Leases	6,182	5,602
Total commercial loans and leases | Commercial and industrial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1	8
Fiscal year before current fiscal year	4	12
Two years before current fiscal year	21	18
Three years before current fiscal year	10	7
Four years before current fiscal year	4	37
Prior	102	42
Revolving Loans Amortized Cost Basis	38	52
Total Loans and Leases	180	176
Total commercial loans and leases | Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2	1
Fiscal year before current fiscal year	17	4
Two years before current fiscal year	10	14
Three years before current fiscal year	15	57
Four years before current fiscal year	50	42
Prior	57	17
Revolving Loans Amortized Cost Basis	51	64
Total Loans and Leases	202	199
Total commercial loans and leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	87	182
Fiscal year before current fiscal year	158	112
Two years before current fiscal year	91	101
Three years before current fiscal year	85	56
Four years before current fiscal year	47	42
Prior	36	2
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	504	495
Total commercial loans and leases | Commercial leases | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	501	493
Total commercial loans and leases | Commercial leases | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	3	2
Total commercial loans and leases | Commercial leases | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	87	182
Fiscal year before current fiscal year	157	109
Two years before current fiscal year	88	98
Three years before current fiscal year	83	53
Four years before current fiscal year	46	39
Prior	36	1
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	497	482
Total commercial loans and leases | Commercial leases | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	1
Two years before current fiscal year	1	0
Three years before current fiscal year	0	2
Four years before current fiscal year	0	3
Prior	0	1
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	1	7
Total commercial loans and leases | Commercial leases | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	1	2
Two years before current fiscal year	2	3
Three years before current fiscal year	2	1
Four years before current fiscal year	1	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	6	6
Total commercial loans and leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	60	39
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	13	3
Revolving Loans Amortized Cost Basis	63	52
Total Loans and Leases	136	94
Total commercial loans and leases | Other | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	136	94
Total commercial loans and leases | Other | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Total commercial loans and leases | Other | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	60	39
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	13	3
Revolving Loans Amortized Cost Basis	63	52
Total Loans and Leases	136	94
Total consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,778	2,801
Fiscal year before current fiscal year	2,926	1,739
Two years before current fiscal year	1,619	772
Three years before current fiscal year	707	466
Four years before current fiscal year	375	379
Prior	1,566	1,272
Revolving Loans Amortized Cost Basis	1,082	1,074
Total Loans and Leases	10,053	8,503
Total consumer loans | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	9,967	8,430
Total consumer loans | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	86	73
Total consumer loans | Direct installment
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	604	978
Fiscal year before current fiscal year	946	538
Two years before current fiscal year	494	216
Three years before current fiscal year	182	126
Four years before current fiscal year	104	96
Prior	439	422
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	2,769	2,376
Total consumer loans | Direct installment | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	604	978
Fiscal year before current fiscal year	945	538
Two years before current fiscal year	493	215
Three years before current fiscal year	182	125
Four years before current fiscal year	103	96
Prior	429	412
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	2,756	2,364
Total consumer loans | Direct installment | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	1	0
Two years before current fiscal year	1	1
Three years before current fiscal year	0	1
Four years before current fiscal year	1	0
Prior	10	10
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	13	12
Total consumer loans | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	701	1,281
Fiscal year before current fiscal year	1,520	933
Two years before current fiscal year	910	393
Three years before current fiscal year	402	155
Four years before current fiscal year	144	215
Prior	918	677
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	4,595	3,654
Total consumer loans | Residential mortgages | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	701	1,280
Fiscal year before current fiscal year	1,518	932
Two years before current fiscal year	907	392
Three years before current fiscal year	401	152
Four years before current fiscal year	141	212
Prior	885	652
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	4,553	3,620
Total consumer loans | Residential mortgages | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	1
Fiscal year before current fiscal year	2	1
Two years before current fiscal year	3	1
Three years before current fiscal year	1	3
Four years before current fiscal year	3	3
Prior	33	25
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	42	34
Total consumer loans | Indirect installment
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	426	522
Fiscal year before current fiscal year	440	265
Two years before current fiscal year	212	159
Three years before current fiscal year	120	180
Four years before current fiscal year	123	65
Prior	63	36
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	1,384	1,227
Total consumer loans | Indirect installment | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	425	516
Fiscal year before current fiscal year	432	262
Two years before current fiscal year	209	157
Three years before current fiscal year	118	178
Four years before current fiscal year	122	64
Prior	62	35
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	1,368	1,212
Total consumer loans | Indirect installment | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1	6
Fiscal year before current fiscal year	8	3
Two years before current fiscal year	3	2
Three years before current fiscal year	2	2
Four years before current fiscal year	1	1
Prior	1	1
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	16	15
Total consumer loans | Consumer lines of credit
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	47	20
Fiscal year before current fiscal year	20	3
Two years before current fiscal year	3	4
Three years before current fiscal year	3	5
Four years before current fiscal year	4	3
Prior	146	137
Revolving Loans Amortized Cost Basis	1,082	1,074
Total Loans and Leases	1,305	1,246
Total consumer loans | Consumer lines of credit | Current
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	47	20
Fiscal year before current fiscal year	20	3
Two years before current fiscal year	3	4
Three years before current fiscal year	3	5
Four years before current fiscal year	4	3
Prior	133	127
Revolving Loans Amortized Cost Basis	1,080	1,072
Total Loans and Leases	1,290	1,234
Total consumer loans | Consumer lines of credit | Past due
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	13	10
Revolving Loans Amortized Cost Basis	2	2
Total Loans and Leases	$ 15	$ 12