PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Changes in Fair Value of Plan Assets (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Actual return on plan assets		$ 226	$ 368	$ 808
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning		5,643	5,614
Adjustment for final fair value of plan assets	$ 57	57	53
Actual return on plan assets		226	368
Foreign currency translation		(155)	(75)
Employer contributions and benefit payments		60	70
Plan participants’ contributions		0	0
Plan transfer/Acquisitions		2	4
Benefits paid (includes lump sum settlements)		(342)	(391)
Fair value of plan assets, ending		5,491	5,643	5,614
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning		0	0
Adjustment for final fair value of plan assets		0	0
Actual return on plan assets		0	0
Foreign currency translation		0	0
Employer contributions and benefit payments		23	31
Plan participants’ contributions		9	13
Plan transfer/Acquisitions		0	0
Benefits paid (includes lump sum settlements)		(32)	(44)
Fair value of plan assets, ending		$ 0	$ 0	$ 0