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]	Treasury Stock [Member]	Noncontrolling Interests
Total Equity, Beginning at Dec. 31, 2016	$ 27,229	$ 3,107	$ 4,262	$ 30,338	$ (9,822)	$ (239)	$ (1,659)	$ 1,242
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income available for The Dow Chemical Company common stockholder	888			888
Other comprehensive income	308				308
Dividends to parent	(557)			(557)
Common stock issued / sold	815		282				533
Stock-based compensation and allocation of ESOP shares	(371)		(407)			36
Impact of noncontrolling interests	32							32
Other	10			(10)
Total Equity, Ending at Mar. 31, 2017	28,334	3,107	4,137	30,659	(9,514)	(203)	(1,126)	1,274
Total Equity, Beginning at Dec. 31, 2017	27,009	0	6,553	28,050	(8,591)	(189)	0	1,186
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income available for The Dow Chemical Company common stockholder	1,342			1,342
Other comprehensive income	483				483
Dividends to parent	(1,057)			(1,057)
Issuance of parent company stock	63		63
Stock-based compensation and allocation of ESOP shares	181		142			39
Impact of noncontrolling interests	4							4
Other	6		0	(6)
Total Equity, Ending at Mar. 31, 2018	$ 27,971	$ 0	$ 6,758	$ 28,261	$ (8,088)	$ (150)	$ 0	$ 1,190