PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Fair Value of Derivatives (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	$ 417	$ 425
Equity index instruments
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	13	29
Forward contracts
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	(32)	(9)
Swaps
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	$ 436	$ 405