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]	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)
Stock Issued									0
Stock-based compensation and allocation of ESOP shares			83			29			83			29
Stock Issued During Period, Value, Parent Company Stock - DWDP			28						28
Net income available for The Dow Chemical Company common stockholder				556						556
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				(535)										$ (535)	$ 0
Transfer of Business Under Common Control	$ 36			35			$ (36)			35
Other				2						(2)
Other comprehensive income	102				102		102				102
Total Equity, Ending at Mar. 31, 2019	33,848	0	7,153	35,403	(9,783)	(105)	33,848	0	7,153	35,403	(9,783)	(105)	$ 1,180
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				(111)						(111)
Total Equity, Beginning at Dec. 31, 2018		0	7,042	35,460	(9,885)	(134)		0	7,042	35,460	(9,885)	(134)
Transfer of Business Under Common Control				14,806						16,009
Total Equity, Ending at Dec. 31, 2019	14,094	8	7,325	17,045	(10,246)	(91)	14,862	0	7,333	17,313	(10,246)	(91)
The Dow Chemical Company’s stockholders’ equity	32,668						32,668
The Dow Chemical Company’s stockholders’ equity	13,541						14,309
Stock Issued									16
Stock-based compensation and allocation of ESOP shares			29			10			29			10
Stock Issued During Period, Value, Parent Company Stock - DWDP			0						0
Net income available for The Dow Chemical Company common stockholder				239						239
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees				0										$ 0	$ (643)
Transfer of Business Under Common Control	0			0			0			0
Other				3						(4)
Other comprehensive income	(283)				(283)		(283)				(283)
Total Equity, Ending at Mar. 31, 2020	13,461	$ 8	$ 7,370	16,763	$ (10,529)	$ (81)	14,228	$ 0	$ 7,378	16,905	$ (10,529)	$ (81)	$ 555
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Period Increase (Decrease) | Adjustments for New Accounting Pronouncement				$ 0						$ 0
The Dow Chemical Company’s stockholders’ equity	$ 12,906						$ 13,673