EMPLOYEE BENEFITS - Schedule of Net Periodic (Income) Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 4	$ 3
Interest cost	50	51	37
Expected return on plan assets	(97)	(92)	(93)
Amortization of actuarial loss	14	17	14
Settlement	3	0	0
Net periodic pension cost (income)	(27)	(20)	(39)
Net actuarial loss (gain)	(26)	(43)	52
Amortization of actuarial loss	(14)	(17)	(14)
Settlement	(3)	0	0
Total recognized in OCI	(43)	(60)	38
Total recognized in net periodic benefit cost (income) and OCI	$ (70)	$ (80)	$ (1)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Noninterest Expense	Other Noninterest Expense	Other Noninterest Expense
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other operating expense	Other operating expense	Other operating expense
Qualified Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 4	$ 3
Interest cost	45	46	34
Expected return on plan assets	(97)	(92)	(93)
Amortization of actuarial loss	13	15	11
Settlement	0	0	0
Net periodic pension cost (income)	(36)	(27)	(45)
Net actuarial loss (gain)	(23)	(44)	71
Amortization of actuarial loss	(13)	(15)	(11)
Settlement	0	0	0
Total recognized in OCI	(36)	(59)	60
Total recognized in net periodic benefit cost (income) and OCI	(72)	(86)	15
Non-Qualified Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	5	5	3
Expected return on plan assets	0	0	0
Amortization of actuarial loss	1	2	3
Settlement	3	0	0
Net periodic pension cost (income)	9	7	6
Net actuarial loss (gain)	(3)	1	(19)
Amortization of actuarial loss	(1)	(2)	(3)
Settlement	(3)	0	0
Total recognized in OCI	(7)	(1)	(22)
Total recognized in net periodic benefit cost (income) and OCI	$ 2	$ 6	$ (16)