EMPLOYEE BENEFITS - Schedule of Net Periodic (Income) Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 3	$ 3
Interest cost	48	48	52
Expected return on plan assets	(68)	(74)	(73)
Amortization of actuarial loss	16	15	10
Net periodic pension (income) cost	(1)	(8)	(8)
Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3
Interest cost	44	44	47
Expected return on plan assets	(68)	(74)	(73)
Amortization of actuarial loss	14	13	9
Net periodic pension (income) cost	(7)	(14)	(14)
Non-Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	4	4	5
Expected return on plan assets	0	0	0
Amortization of actuarial loss	2	2	1
Net periodic pension (income) cost	$ 6	$ 6	$ 6