STOCKHOLDERS' EQUITY (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (9,885)	$ (8,591)
Total other comprehensive income (loss)	(1,154)	(257)	$ 1,231
Settlements and transfers related to separation from DowDuPont Inc.	(1,935)	240	(6)
Ending Balance	(10,246)	(9,885)	(8,591)
Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(51)	17	43
Other Comprehensive Income (Loss), before Reclassifications, before Tax	178	(93)	38
Other Comprehensive Income (Loss) before Reclassifications, Tax	(38)	19	(13)
Other comprehensive income (loss) before reclassifications	140	(74)	25
Total other comprehensive income (loss)	115	(67)	(46)
Ending Balance	64	(51)	17
Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,813)	(1,481)	(2,381)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	59	(215)	1,006
Other Comprehensive Income (Loss) before Reclassifications, Tax	(2)	(6)	(98)
Other comprehensive income (loss) before reclassifications	57	(221)	908
Total other comprehensive income (loss)	(32)	(225)	900
Ending Balance	(1,135)	(1,813)	(1,481)
Pension and Other Postretire Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7,965)	(6,998)	(7,389)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(1,699)	(625)	(3)
Other Comprehensive Income (Loss) before Reclassifications, Tax	413	130	(20)
Other comprehensive income (loss) before reclassifications	(1,286)	(495)	(23)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	504	594	607
Reclassification from AOCI, Current Period, Tax	(117)	(139)	(193)
Amounts reclassified from accumulated other comprehensive income (loss)	387	455	414
Total other comprehensive income (loss)	(899)	(40)	391
Ending Balance	(8,781)	(7,965)	(6,998)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(56)	(109)	(95)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(470)	6	2
Other Comprehensive Income (Loss) before Reclassifications, Tax	101	(2)	(1)
Other comprehensive income (loss) before reclassifications	(369)	4	1
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	44	89	(13)
Reclassification from AOCI, Current Period, Tax	(13)	(18)	(2)
Amounts reclassified from accumulated other comprehensive income (loss)	31	71	(15)
Total other comprehensive income (loss)	(338)	75	(14)
Ending Balance	(394)	(56)	(109)
Accounting Standards Update 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 20
Retained Earnings [Member] | Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Adoption of accounting standards (Note 1)	0	(1)	0
Retained Earnings [Member] | Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlements and transfers related to separation from DowDuPont Inc.	710	0	0
Adoption of accounting standards (Note 1)	0	(107)	0
Retained Earnings [Member] | Pension and Other Postretire Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlements and transfers related to separation from DowDuPont Inc.	83	0	0
Adoption of accounting standards (Note 1)	0	(927)	0
Retained Earnings [Member] | Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Adoption of accounting standards (Note 1)	0	(22)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(33)	9	(110)
Reclassification from AOCI, Current Period, Tax	8	(2)	39
Amounts reclassified from accumulated other comprehensive income (loss)	(25)	7	(71)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	$ (89)	(4)	(8)
Previously Reported [Member] | Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		$ (3)
Ending Balance			$ (3)