EMPLOYEE BENEFIT PLANS - NET PENSION EXPENSE (Details) - Qualified Defined Benefit [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 15
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	10	$ 9	$ 30	$ 27
Interest cost	19	18	55	55
Expected return on assets	(27)	(27)	(80)	(81)
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Recognized actuarial loss (gain)	7	7	20	19
Net pension expense	$ 8	$ 6	$ 24	$ 19