Dow Consolidated Statements of Income Statement - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 14,837	$ 9,712	$ 40,604	$ 27,836
Cost of sales	11,611	8,371	32,413	24,211
Research and development expenses	210	193	632	554
Selling, general and administrative expenses	403	372	1,209	1,063
Amortization of intangibles	100	100	301	300
Restructuring and asset related charges - net	0	617	22	719
Integration and separation costs	0	63	0	174
Equity in earnings (losses) of nonconsolidated affiliates	249	60	751	(124)
Sundry income (expense) - net	(350)	182	(225)	154
Interest income	14	6	35	27
Interest expense and amortization of debt discount	178	202	561	617
Income before income taxes	2,248	42	6,027	255
Provision for income taxes	542	43	1,383	215
Net income attributable to noncontrolling interests	23	24	69	51
Net income (loss) available for The Dow Chemical Company common stockholder	$ 1,683	$ (25)	$ 4,575	$ (11)
Earnings (loss) per common share - basic	$ 2.25	$ (0.04)	$ 6.11	$ (0.02)
Earnings (loss) per common share - diluted	$ 2.23	$ (0.04)	$ 6.06	$ (0.02)
Weighted-average common shares outstanding - basic	744.5	740.5	745.4	740.0
Weighted-average common shares outstanding - diluted	750.0	740.5	750.9	740.0