Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (9,941)	$ (9,219)	$ (9,941)	$ (9,219)		$ (10,246)
Other Comprehensive Income (Loss), Net of Tax	284	(231)	305	(127)
Settlements and transfers related to separation from DowDuPont Inc.			0	1,935
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	48	60	48	60	$ 40	64	$ 49	$ (51)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	35	20	39	158
Other Comprehensive Income (Loss), Tax	(8)	(4)	(10)	(33)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	27	16	29	125
Other Comprehensive Income (Loss), Net of Tax	8	11	(16)	111
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(25)	(6)	(59)	(18)
Reclassification from AOCI, Current Period, Tax	6	1	14	4
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(19)	(5)	(45)	(14)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(1,144)	(1,283)	(1,144)	(1,283)	(1,235)	(1,135)	(1,067)	(1,813)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	116	(164)	18	(100)
Other Comprehensive Income (Loss), Tax	4	(26)	18	(12)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	120	(190)	36	(112)
Other Comprehensive Income (Loss), Net of Tax	91	(216)	(9)	(180)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Retained Earnings [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlements and transfers related to separation from DowDuPont Inc.	0	0	0	710
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(29)	(26)	(45)	(68)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(8,351)	(7,527)	(8,351)	(7,527)	(8,498)	(8,781)	(7,635)	(7,965)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	2	0	2	34
Other Comprehensive Income (Loss), Tax	0	0	0	(10)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	2	0	2	24
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	188	139	557	413
Reclassification from AOCI, Current Period, Tax	(43)	(31)	(129)	(82)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	145	108	428	331
Other Comprehensive Income (Loss), Net of Tax	147	108	430	355
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Retained Earnings [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlements and transfers related to separation from DowDuPont Inc.	0	0	0	83
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(494)	(469)	(494)	(469)	$ (532)	$ (394)	$ (335)	$ (56)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	45	(187)	(114)	(545)
Other Comprehensive Income (Loss), Tax	(10)	37	(2)	110
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	35	(150)	(116)	(435)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	5	20	24	30
Reclassification from AOCI, Current Period, Tax	(2)	(4)	(8)	(8)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	3	16	16	22
Other Comprehensive Income (Loss), Net of Tax	$ 38	$ (134)	$ (100)	$ (413)