CREDIT QUALITY AND THE ALLOWANCE FOR CREDIT LOSSES - Accruing and Non-accruing Past Due Amounts (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Loans and leases	$ 142,692	$ 139,203
Loans and leases, nonaccrual	1,504	1,664
Loans and leases, nonaccrual with no related ACL	496	398
FHA, VA And USDA Loans
Financing Receivable, Past Due [Line Items]
Loans and leases	964	1,042
Loans and leases, nonaccrual	0	0
Loans and leases, nonaccrual with no related ACL	0	0
Financing Receivables, Current
Financing Receivable, Past Due [Line Items]
Loans and leases	140,248	136,320
Financing Receivables, Current | FHA, VA And USDA Loans
Financing Receivable, Past Due [Line Items]
Loans and leases	743	696
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	565	769
Financing Receivables, 30 to 59 Days Past Due | FHA, VA And USDA Loans
Financing Receivable, Past Due [Line Items]
Loans and leases	53	119
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	206	254
Financing Receivables, 60 to 89 Days Past Due | FHA, VA And USDA Loans
Financing Receivable, Past Due [Line Items]
Loans and leases	27	55
Financing Receivables, 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	169	196
Financing Receivables, 90 Days or More Past Due | FHA, VA And USDA Loans
Financing Receivable, Past Due [Line Items]
Loans and leases	141	172
Commercial
Financing Receivable, Past Due [Line Items]
Loans and leases	73,812	69,776
Loans and leases, nonaccrual	895	1,017
Loans and leases, nonaccrual with no related ACL	119	63
Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and leases	49,232	42,551
Loans and leases, nonaccrual	277	241
Loans and leases, nonaccrual with no related ACL	34	31
Commercial | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and leases	24,580	27,225
Loans and leases, nonaccrual	618	776
Loans and leases, nonaccrual with no related ACL	85	32
Commercial | Financing Receivables, Current
Financing Receivable, Past Due [Line Items]
Loans and leases	72,573	68,459
Commercial | Financing Receivables, Current | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and leases	48,873	42,247
Commercial | Financing Receivables, Current | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and leases	23,700	26,212
Commercial | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	247	239
Commercial | Financing Receivables, 30 to 59 Days Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and leases	63	35
Commercial | Financing Receivables, 30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and leases	184	204
Commercial | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	72	47
Commercial | Financing Receivables, 60 to 89 Days Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and leases	14	20
Commercial | Financing Receivables, 60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and leases	58	27
Commercial | Financing Receivables, 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	25	14
Commercial | Financing Receivables, 90 Days or More Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and leases	5	8
Commercial | Financing Receivables, 90 Days or More Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and leases	20	6
Retail
Financing Receivable, Past Due [Line Items]
Loans and leases	68,880	69,427
Loans and leases, nonaccrual	609	647
Loans and leases, nonaccrual with no related ACL	377	335
Retail | Residential mortgages
Financing Receivable, Past Due [Line Items]
Loans and leases	35,024	32,726
Loans and leases, nonaccrual	196	192
Loans and leases, nonaccrual with no related ACL	155	142
Retail | Home equity
Financing Receivable, Past Due [Line Items]
Loans and leases	19,069	16,495
Loans and leases, nonaccrual	319	283
Loans and leases, nonaccrual with no related ACL	215	182
Retail | Automobile
Financing Receivable, Past Due [Line Items]
Loans and leases	2,310	4,744
Loans and leases, nonaccrual	28	48
Loans and leases, nonaccrual with no related ACL	4	6
Retail | Education
Financing Receivable, Past Due [Line Items]
Loans and leases	8,416	10,812
Loans and leases, nonaccrual	20	56
Loans and leases, nonaccrual with no related ACL	2	4
Retail | Other retail
Financing Receivable, Past Due [Line Items]
Loans and leases	4,061	4,650
Loans and leases, nonaccrual	46	68
Loans and leases, nonaccrual with no related ACL	1	1
Retail | Financing Receivables, Current
Financing Receivable, Past Due [Line Items]
Loans and leases	67,675	67,861
Retail | Financing Receivables, Current | Residential mortgages
Financing Receivable, Past Due [Line Items]
Loans and leases	34,547	32,011
Retail | Financing Receivables, Current | Home equity
Financing Receivable, Past Due [Line Items]
Loans and leases	18,626	16,097
Retail | Financing Receivables, Current | Automobile
Financing Receivable, Past Due [Line Items]
Loans and leases	2,203	4,563
Retail | Financing Receivables, Current | Education
Financing Receivable, Past Due [Line Items]
Loans and leases	8,342	10,686
Retail | Financing Receivables, Current | Other retail
Financing Receivable, Past Due [Line Items]
Loans and leases	3,957	4,504
Retail | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	318	530
Retail | Financing Receivables, 30 to 59 Days Past Due | Residential mortgages
Financing Receivable, Past Due [Line Items]
Loans and leases	93	251
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity
Financing Receivable, Past Due [Line Items]
Loans and leases	95	88
Retail | Financing Receivables, 30 to 59 Days Past Due | Automobile
Financing Receivable, Past Due [Line Items]
Loans and leases	59	100
Retail | Financing Receivables, 30 to 59 Days Past Due | Education
Financing Receivable, Past Due [Line Items]
Loans and leases	36	45
Retail | Financing Receivables, 30 to 59 Days Past Due | Other retail
Financing Receivable, Past Due [Line Items]
Loans and leases	35	46
Retail | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	134	207
Retail | Financing Receivables, 60 to 89 Days Past Due | Residential mortgages
Financing Receivable, Past Due [Line Items]
Loans and leases	47	93
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity
Financing Receivable, Past Due [Line Items]
Loans and leases	28	27
Retail | Financing Receivables, 60 to 89 Days Past Due | Automobile
Financing Receivable, Past Due [Line Items]
Loans and leases	20	33
Retail | Financing Receivables, 60 to 89 Days Past Due | Education
Financing Receivable, Past Due [Line Items]
Loans and leases	16	23
Retail | Financing Receivables, 60 to 89 Days Past Due | Other retail
Financing Receivable, Past Due [Line Items]
Loans and leases	23	31
Retail | Financing Receivables, 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	144	182
Retail | Financing Receivables, 90 Days or More Past Due | Residential mortgages
Financing Receivable, Past Due [Line Items]
Loans and leases	141	179
Retail | Financing Receivables, 90 Days or More Past Due | Home equity
Financing Receivable, Past Due [Line Items]
Loans and leases	1	0
Retail | Financing Receivables, 90 Days or More Past Due | Automobile
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Retail | Financing Receivables, 90 Days or More Past Due | Education
Financing Receivable, Past Due [Line Items]
Loans and leases	2	2
Retail | Financing Receivables, 90 Days or More Past Due | Other retail
Financing Receivable, Past Due [Line Items]
Loans and leases	$ 0	$ 1