Consolidated Statements of Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Add'l Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Unearned ESOP	Treasury Stock	Noncontrolling Interests
Beginning balance at Dec. 31, 2015	$ 26,183	$ 4,000	$ 3,107	$ 4,936	$ 28,425	$ (8,667)	$ (272)	$ (6,155)	$ 809
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income available for The Dow Chemical Company common stockholder	3,978				3,978
Other comprehensive Income (loss)	(1,155)					(1,155)
Dividends to stockholders	(2,037)				(2,037)
Common stock issued/sold	1,115			398				717
Stock-based compensation and allocation of ESOP shares	(325)			(376)			51
ESOP shares acquired	(18)						(18)
Impact of noncontrolling interests	433								433
Treasury stock purchases	(916)							(916)
Preferred stock converted to common stock		(4,000)		695				4,695
Other	(29)			(1)	(28)
Ending balance at Dec. 31, 2016	27,229	0	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	466				466
Other comprehensive Income (loss)	1,231					1,231
Dividends to stockholders	(1,673)				(1,673)
Dividends to parent	(1,056)				(1,056)
Common stock issued/sold	1,147			423				724
Issuance of parent company stock	66			66
Stock-based compensation and allocation of ESOP shares	(318)			(368)			50
Impact of noncontrolling interests	(56)								(56)
Merger impact	0		3,107	2,172				935
Other	(27)			(2)	(25)
Ending balance at Dec. 31, 2017	27,009	0	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	4,499				4,499
Other comprehensive Income (loss)	(257)					(257)
Dividends to parent	(3,711)				(3,711)
Issuance of parent company stock	112			112
Stock-based compensation and allocation of ESOP shares	432			377			55
Impact of noncontrolling interests	(48)								(48)
Other	(19)			0	(19)
Ending balance at Dec. 31, 2018	$ 27,969	$ 0	$ 0	$ 7,042	$ 29,808	$ (9,885)	$ (134)	$ 0	$ 1,138