STOCKHOLDERS' EQUITY (Accumulated Other Comprehensive Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (10,246)	$ (9,885)
Total other comprehensive loss	(609)	(1,154)	$ (257)
Settlements and transfers related to separation from DowDuPont Inc.	0	(1,935)	240
Ending Balance	(10,855)	(10,246)	(9,885)
Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	64	(51)	17
Other Comprehensive Income (Loss), before Reclassifications, before Tax	104	178	(93)
Other Comprehensive Income (Loss) before Reclassifications, Tax	(23)	(38)	19
Other comprehensive income (loss) before reclassifications	81	140	(74)
Total other comprehensive loss	40	115	(67)
Ending Balance	104	64	(51)
Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,135)	(1,813)	(1,481)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	227	59	(215)
Other Comprehensive Income (Loss) before Reclassifications, Tax	25	(2)	(6)
Other comprehensive income (loss) before reclassifications	252	57	(221)
Total other comprehensive loss	205	(32)	(225)
Ending Balance	(930)	(1,135)	(1,813)
Pension and Other Postretire Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(8,781)	(7,965)	(6,998)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(1,769)	(1,699)	(625)
Other Comprehensive Income (Loss) before Reclassifications, Tax	411	413	130
Other comprehensive income (loss) before reclassifications	(1,358)	(1,286)	(495)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	753	504	594
Reclassification from AOCI, Current Period, Tax	(173)	(117)	(139)
Amounts reclassified from accumulated other comprehensive income (loss)	580	387	455
Total other comprehensive loss	(778)	(899)	(40)
Ending Balance	(9,559)	(8,781)	(7,965)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(394)	(56)	(109)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(96)	(470)	6
Other Comprehensive Income (Loss) before Reclassifications, Tax	(1)	101	(2)
Other comprehensive income (loss) before reclassifications	(97)	(369)	4
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	30	44	89
Reclassification from AOCI, Current Period, Tax	(9)	(13)	(18)
Amounts reclassified from accumulated other comprehensive income (loss)	21	31	71
Total other comprehensive loss	(76)	(338)	75
Ending Balance	(470)	(394)	(56)
Retained Earnings [Member] | Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlements and transfers related to separation from DowDuPont Inc.	0	710	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.	0	83	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	(54)	(33)	9
Reclassification from AOCI, Current Period, Tax	13	8	(2)
Amounts reclassified from accumulated other comprehensive income (loss)	(41)	(25)	7
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)	(47)	(89)	(4)
Revision of Prior Period, Accounting Standards Update, Adjustment | Retained Earnings [Member] | Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	0	0	(1)
Revision of Prior Period, Accounting Standards Update, Adjustment | Retained Earnings [Member] | Cumulative Translation Adj
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	0	0	(107)
Revision of Prior Period, Accounting Standards Update, Adjustment | Retained Earnings [Member] | Pension and Other Postretire Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	0	0	(927)
Revision of Prior Period, Accounting Standards Update, Adjustment | Retained Earnings [Member] | Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	$ 0	$ 0	$ (22)