PENSION AND POSTRETIREMENT BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Decrease to liabilities and a corresponding decrease in accumulated other comprehensive loss	$ (412)	$ 49	$ (292)	$ 299
Weighted average discount rate assumed in remeasuring the pension benefit obligations			4.30%			3.80%
Defined contribution plan expense	45	46	$ 89	96
Pension Benefits [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Service cost - benefits earned during the period	6	10	12	20
Interest cost on projected benefit obligation	60	77	121	155
Expected return on plan assets	(103)	(133)	(205)	(264)
Amortization of prior service credits	(1)	(1)	(2)	(2)
Amortization of net actuarial loss	26	29	50	56
Pension curtailments and settlements	36	45	63	99
Special termination benefits				13
Net periodic cost/(credit)	24	27	39	77
Expected contributions to pension plans					$ 100
Contributions to pension plan			62
Other Benefits [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Service cost - benefits earned during the period	1	1	2	2
Interest cost on projected benefit obligation	3	4	6	7
Expected return on plan assets	(6)	(7)	(13)	(14)
Amortization of prior service credits	(2)	(1)	(3)	(1)
Amortization of net actuarial loss	1		2
Pension curtailments and settlements				(3)
Net periodic cost/(credit)	$ (3)	$ (3)	$ (6)	$ (9)