Dow Consolidated Statements of Income Statement - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 13,885	$ 8,354	$ 25,767	$ 18,124
Cost of sales	10,740	7,610	20,802	15,840
Research and development expenses	228	182	422	361
Selling, general and administrative expenses	440	357	806	691
Amortization of intangibles	100	100	201	200
Restructuring and asset related charges - net	22	6	22	102
Integration and separation costs	0	46	0	111
Equity in earnings (losses) of nonconsolidated affiliates	278	(95)	502	(184)
Sundry income (expense) - net	(3)	53	125	(28)
Interest income	13	6	21	21
Interest expense and amortization of debt discount	187	200	383	415
Income (loss) before income taxes	2,456	(183)	3,779	213
Provision for income taxes	524	34	841	172
Net income (loss)	1,932	(217)	2,938	41
Net income attributable to noncontrolling interests	31	8	46	27
Net income (loss) available for The Dow Chemical Company common stockholder	$ 1,901	$ (225)	$ 2,892	$ 14
Earnings (loss) per common share - basic	$ 2.53	$ (0.31)	$ 3.86	$ 0.01
Earnings (loss) per common share - diluted	$ 2.51	$ (0.31)	$ 3.83	$ 0.01
Weighted-average common shares outstanding - basic	747.0	739.3	745.9	739.7
Weighted-average common shares outstanding - diluted	752.9	739.3	751.4	741.0