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	2,209			2,209
Other comprehensive income	748				748
Dividends to parent	(1,115)			(1,115)
Common stock issued / sold	983		357				626
Stock-based compensation and allocation of ESOP shares	(374)		(415)			41
Impact of noncontrolling interests	(74)							(74)
Other	(17)		(2)	15
Total Equity, Ending at Jun. 30, 2017	29,589	3,107	4,202	31,417	(9,074)	(198)	(1,033)	1,168
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	2,621			2,621
Other comprehensive income	241				241
Dividends to parent	(2,110)			(2,110)
Issuance of parent company stock	85		85
Stock-based compensation and allocation of ESOP shares	267		223			44
Impact of noncontrolling interests	(34)							(34)
Other	(14)		0	14
Total Equity, Ending at Jun. 30, 2018	$ 28,017	$ 0	$ 6,861	$ 29,536	$ (9,387)	$ (145)	$ 0	$ 1,152