Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss	Unearned ESOP Shares [Member]	Dow Inc. [Member] Retained Earnings [Member]	The Dow Chemical Company	The Dow Chemical Company Common Stock [Member]	The Dow Chemical Company Additional Paid-in Capital [Member]	The Dow Chemical Company Retained Earnings [Member]	The Dow Chemical Company Accumulated Other Comprehensive Loss	The Dow Chemical Company Unearned ESOP Shares [Member]	The Dow Chemical Company Noncontrolling Interests
Total Equity, Beginning at Dec. 31, 2019		$ 8	$ 7,325	$ 17,045	$ (10,246)	$ (91)			$ 0	$ 7,333	$ 17,313	$ (10,246)	$ (91)
Stock Issued										30
Stock-based compensation and allocation of ESOP shares			76			22				76			22
Net income available for The Dow Chemical Company common stockholder	$ 10			14							14
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees							$ (1,172)
Other				8							(8)
Other comprehensive income	21				21			$ 21				21
Total Equity, Ending at Jun. 30, 2020	13,097	8	7,431	16,017	(10,225)	(69)		13,852	0	7,439	16,147	(10,225)	(69)	$ 560
Total Equity, Beginning at Mar. 31, 2020		8	7,370	16,763	(10,529)	(81)			0	7,378	16,905	(10,529)	(81)
Stock Issued										14
Stock-based compensation and allocation of ESOP shares			47			12				47			12
Net income available for The Dow Chemical Company common stockholder	(227)			(225)							(225)
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees							(529)
Other				5							(4)
Other comprehensive income	304				304			304				304
Total Equity, Ending at Jun. 30, 2020	13,097	8	7,431	16,017	(10,225)	(69)		13,852	0	7,439	16,147	(10,225)	(69)	560
The Dow Chemical Company’s stockholders’ equity	12,537							13,292
The Dow Chemical Company’s stockholders’ equity	12,435							12,999
Total Equity, Beginning at Dec. 31, 2020	13,005	8	7,595	16,361	(10,855)	(49)		13,569	0	7,603	16,300	(10,855)	(49)
Stock Issued										200
Stock-based compensation and allocation of ESOP shares			103			17				103			17
Net income available for The Dow Chemical Company common stockholder	2,877			2,892							2,897
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees							(1,442)
Other				10							(10)
Other comprehensive income	1,179				1,179			1,179				1,179
Total Equity, Ending at Jun. 30, 2021	16,153	8	7,898	18,200	(9,676)	(32)		16,523	0	7,906	17,745	(9,676)	(32)	580
Total Equity, Beginning at Mar. 31, 2021		8	7,743	16,829	(9,913)	(39)			0	7,751	16,577	(9,913)	(39)
Stock Issued										73
Stock-based compensation and allocation of ESOP shares			82			7				82			7
Net income available for The Dow Chemical Company common stockholder	1,891			1,901							1,914
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees							$ (739)
Other				8							(7)
Other comprehensive income	237				237			237				237
Total Equity, Ending at Jun. 30, 2021	16,153	$ 8	$ 7,898	$ 18,200	$ (9,676)	$ (32)		16,523	$ 0	$ 7,906	$ 17,745	$ (9,676)	$ (32)	$ 580
The Dow Chemical Company’s stockholders’ equity	$ 15,573							$ 15,943