FINANCIAL INSTRUMENTS - Effects of Derivative on Earnings (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Pre-tax gain included in AOCI related to cash flow hedges of forecasted transactions	$ 98
Amount of loss expected to be transferred to earnings as an expense	$ 30
Maximum term of hedged forecasted transactions	15 years	16 years	17 years