EMPLOYEE BENEFIT PLANS - NET PENSION EXPENSE (Details) - Qualified Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 41	$ 33	$ 46
Interest cost	84	81	73
Expected return on assets	(122)	(117)	(111)
Amortization of prior service cost	(1)	(1)	(1)
Recognized actuarial loss	26	13	43
Settlement expense (special item)	(14)	0	0
Net periodic benefit cost	42	9	$ 50
Plan settlement	$ 62	$ 0