EMPLOYEE BENEFIT PLANS - NET PENSION EXPENSE (Details) - Qualified Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 48	$ 39	$ 37
Interest cost	79	74	73
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	107	106	108
Amortization of prior service cost	(1)	(1)	(1)
Defined Benefit Plan, Amortization of Gain (Loss)	(33)	(26)	(25)
Net pension expense	$ 52	$ 32	$ 26