FINANCIAL INSTRUMENTS - Cash Flow Hedge Activity (Details) - Cash Flow Hedges - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Derivative [Line Items]
Gain (loss) recognized in AOCI	$ 47	$ 142
Gain (loss) reclassified from AOCI into earnings	0	65
Interest rate contracts
Derivative [Line Items]
Gain (loss) recognized in AOCI	4	(4)
Gain (loss) reclassified from AOCI into earnings	(3)	(2)
Currency exchange contracts
Derivative [Line Items]
Gain (loss) recognized in AOCI	43	146
Gain (loss) reclassified from AOCI into earnings	$ 3	$ 66

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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