PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 9	$ 10	$ 18	$ 20
Interest cost	36	32	72	64
Expected return on plan assets	(53)	(54)	(106)	(109)
Amortization of net (gain) loss	21	23	42	47
Net periodic benefit cost	13	11	26	22
Other Postretirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	2	1	4	3
Amortization of net (gain) loss	(2)	(2)	(4)	(4)
Net periodic benefit cost	$ 0	$ (1)	$ 0	$ (1)