Pension Plans and Other Post Employment Benefit Plans Components of net periodic benefit cost (credit) and amounts recognized in other comprehensive loss (Details) - USD ($) $ in Millions		4 Months Ended	8 Months Ended	12 Months Ended
		Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		$ (34)	$ (18)	$ (31)	$ (97)
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost		50	92	41	136
Interest Cost		247	524	769	755
Expected return on plan assets		(411)	(824)	(1,078)	(1,216)
Amortization of unrecognized loss (gain)		1	506	3	10
Amortization of prior service benefit		0	(3)	(1)	0
Curtailment gain		0	0	(2)	(11)
Settlement loss		0	0	4	5
Net periodic benefit cost (credit)		(113)	295	(264)	(321)
Net loss (gain)		(163)	(22)	970	908
Amortization of unrecognized (loss) gain		(1)	(506)	(2)	(10)
Prior service cost (benefit)		0	0	(11)	17
Amortization of prior service benefit		0	3	1	0
Settlement loss		0	0	(4)	(2)
Effect of foreign exchange rates		3	133	(5)	1
Total (benefit) loss recognized in other comprehensive loss, attributable to Corteva		(161)	(392)	949	914
Total recognized in net periodic benefit cost and other comprehensive (income) loss		(274)	(97)	685	593
Other Post Employment Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost		3	6	4	9
Interest Cost		26	60	84	85
Expected return on plan assets		0	0	0	0
Amortization of unrecognized loss (gain)		0	61	(1)	0
Amortization of prior service benefit		0	(46)	0	0
Curtailment gain		0	0	0	0
Settlement loss		0	0	0	0
Net periodic benefit cost (credit)		29	81	87	94
Net loss (gain)		68	0	211	(172)
Amortization of unrecognized (loss) gain		0	(61)	1	0
Prior service cost (benefit)		0	0	0	0
Amortization of prior service benefit		0	46	0	0
Settlement loss		0	0	0	0
Effect of foreign exchange rates		0	0	0	0
Total (benefit) loss recognized in other comprehensive loss, attributable to Corteva		68	(15)	212	(172)
Total recognized in net periodic benefit cost and other comprehensive (income) loss		97	66	299	(78)
Discontinued Operations [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)	[1]	(13)	27	(14)	(42)
Discontinued Operations [Member] | Other Post Employment Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)	[1]	0	0	0	1
Continuing Operations [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)		(100)	268	(250)	(279)
Continuing Operations [Member] | Other Post Employment Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)		$ 29	$ 81	$ 87	$ 93

[1] ncludes non-service related components of net periodic benefit credit of $(31) million, $(97) million, $(34) million, and $(18) million for the year ended December 31, 2019, the year ended December 31, 2018, the period September 1 through December 31, 2017, and the period January 1 through August 31, 2017, respectively.