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
Total Equity, Beginning at Dec. 31, 2017		$ 0	$ 6,553	$ 33,742	$ (8,591)	$ (189)				$ 6,553	$ 33,742	$ (8,591)	$ (189)
Stock Issued										0
Stock-based compensation and allocation of ESOP shares			223			44				223			44
Adjustments to Additional Paid in Capital, Other										0
Stock Issued During Period, Value, Parent Company Stock - DWDP			85							85
Net income available for The Dow Chemical Company common stockholder				2,737							2,737
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				(2,110)							2,110
Transfer of Business Under Common Control	$ 215			(152)	0		$ 0	$ (215)			(152)	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				989	(1,037)						989	(1,037)
Other			0	14							(14)
Other comprehensive income	241				241			241				241
Total Equity, Ending at Jun. 30, 2018	33,673	0	6,861	35,192	(9,387)	(145)		33,673	$ 0	6,861	35,192	(9,387)	(145)	$ 1,152
Total Equity, Beginning at Mar. 31, 2018		0	6,758	33,899	(8,088)	(150)				6,758	33,899	(8,088)	(150)
Stock Issued										0
Stock-based compensation and allocation of ESOP shares			81			5				81			5
Adjustments to Additional Paid in Capital, Other										0
Stock Issued During Period, Value, Parent Company Stock - DWDP			22							22
Net income available for The Dow Chemical Company common stockholder				1,333							1,333
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				(1,053)							1,053
Transfer of Business Under Common Control				(37)	0		0				(37)	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				1,057	(1,057)						1,057	(1,057)
Other			0	7							(7)
Other comprehensive income	(242)				(242)			(242)				(242)
Total Equity, Ending at Jun. 30, 2018	33,673	0	6,861	35,192	(9,387)	(145)		33,673	0	6,861	35,192	(9,387)	(145)	1,152
The Dow Chemical Company’s stockholders’ equity	32,521							32,521
The Dow Chemical Company’s stockholders’ equity	32,483							32,483
Total Equity, Beginning at Dec. 31, 2018	33,621	0	7,042	35,460	(9,885)	(134)		33,621		7,042	35,460	(9,885)	(134)
Stock Issued										6
Stock-based compensation and allocation of ESOP shares			147			35				147			35
Adjustments to Additional Paid in Capital, Other										(31)
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
Transfer of Business Under Common Control	(1,963)			(14,811)	(793)		(353)	(61)			(15,990)	(793)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(111)	0						(111)	0
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
Total Equity, Beginning at Mar. 31, 2019		0	7,153	35,403	(9,783)	(105)				7,153	35,403	(9,783)	(105)
Stock Issued										6
Stock-based compensation and allocation of ESOP shares			64			6				64			6
Adjustments to Additional Paid in Capital, Other										(31)
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
Transfer of Business Under Common Control				(14,846)	(793)		$ (353)				(16,025)	(793)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				0	0						0	0
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
The Dow Chemical Company’s stockholders’ equity	$ 17,911							$ 17,680