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]	Noncontrolling Interests	The Dow Chemical Company [Domain]	The Dow Chemical Company [Domain] Common Stock [Member]	The Dow Chemical Company [Domain] Additional Paid-in Capital [Member]	The Dow Chemical Company [Domain] Retained Earnings [Member]	The Dow Chemical Company [Domain] Accumulated Other Comprehensive Loss	The Dow Chemical Company [Domain] Unearned ESOP Shares [Member]	The Dow Chemical Company [Domain] Noncontrolling Interests	DowDuPont [Member] Retained Earnings [Member]	Dow Inc. [Member] Retained Earnings [Member]
Total Equity, Beginning at Dec. 31, 2018		$ 0	$ 7,042	$ 35,460	$ (9,885)	$ (134)			$ 0	$ 7,042	$ 35,460	$ (9,885)	$ (134)
Total Equity, Ending at Mar. 31, 2019		0	7,153	35,403	(9,783)	(105)			0	7,153	35,403	(9,783)	(105)
Total Equity, Beginning at Dec. 31, 2018		0	7,042	35,460	(9,885)	(134)			0	7,042	35,460	(9,885)	(134)
Stock Issued										6
Stock-based compensation and allocation of ESOP shares			147			35				147			35
Stock Issued During Period, Value, Parent Company Stock - DWDP			28							28
Net income available for The Dow Chemical Company common stockholder				631							758
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				(535)											$ (535)	$ 0
Impact of common control transaction 2	$ (1,963)			(14,811)	(793)		$ (353)	$ (61)			(15,990)	(793)
Other			30	7							(7)
Other comprehensive income	104				104			104				104
Total Equity, Ending at Jun. 30, 2019	18,500	7	7,186	20,110	(8,988)	(99)		18,269	0	7,192	19,575	(8,988)	(99)	$ 589
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				(111)							(111)
Adjustments to Additional Paid in Capital, Other										(31)
Total Equity, Beginning at Mar. 31, 2019		0	7,153	35,403	(9,783)	(105)			0	7,153	35,403	(9,783)	(105)
Stock Issued										6
Stock-based compensation and allocation of ESOP shares			64			6				64			6
Stock Issued During Period, Value, Parent Company Stock - DWDP			0							0
Net income available for The Dow Chemical Company common stockholder				75							202
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				0							0					0
Impact of common control transaction 2				(14,846)	(793)		(353)				(16,025)	(793)
Other			30	5							(5)
Other comprehensive income	2				2			2				2
Total Equity, Ending at Jun. 30, 2019	18,500	7	7,186	20,110	(8,988)	(99)		18,269	0	7,192	19,575	(8,988)	(99)	589
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				0							0
Adjustments to Additional Paid in Capital, Other										(31)
The Dow Chemical Company’s stockholders’ equity	17,911							17,680
The Dow Chemical Company’s stockholders’ equity	13,541							14,309
Total Equity, Beginning at Dec. 31, 2019	14,094	8	7,325	17,045	(10,246)	(91)		14,862	0	7,333	17,313	(10,246)	(91)
Stock Issued										30
Stock-based compensation and allocation of ESOP shares			76			22				76			22
Stock Issued During Period, Value, Parent Company Stock - DWDP			0							0
Net income available for The Dow Chemical Company common stockholder				14							14
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				0											$ 0	(1,172)
Impact of common control transaction 2	0			0	0		0	0			0	0
Other			0	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				0							0
Adjustments to Additional Paid in Capital, Other										0
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
Stock Issued During Period, Value, Parent Company Stock - DWDP			0							0
Net income available for The Dow Chemical Company common stockholder				(225)							(225)
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				0							0					$ (529)
Impact of common control transaction 2				0	0		$ 0				0	0
Other			0	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				$ 0							$ 0
Adjustments to Additional Paid in Capital, Other										$ 0
The Dow Chemical Company’s stockholders’ equity	$ 12,537							$ 13,292