PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Aggregate Notional Amount of Derivatives (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Notional Amount of Derivatives	$ 2,720	$ 2,605
Equity index instruments
Defined Benefit Plan Disclosure [Line Items]
Notional Amount of Derivatives	361	399
Forward contracts
Defined Benefit Plan Disclosure [Line Items]
Notional Amount of Derivatives	535	638
Swaps
Defined Benefit Plan Disclosure [Line Items]
Notional Amount of Derivatives	$ 1,824	$ 1,568