PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 125	$ 104
Interest cost	219	197
Expected return on plan assets	(383)	(342)
Amortization of prior service credit	(6)	(6)
Amortization of net (gain) loss	157	146
Net periodic benefit cost	112	99
Other Postretirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	3	3
Interest cost	14	12
Amortization of prior service credit	0	(1)
Amortization of net (gain) loss	(2)	(2)
Net periodic benefit cost	$ 15	$ 12