Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Add'l Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Unearned ESOP	Treasury Stock
Dividends declared per share of common stock	$ 1.38
Beginning balance at Dec. 31, 2016		$ 3,107	$ 4,262	$ 30,338	$ (9,822)	$ (239)	$ (1,659)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Merger impact		3,107	2,172				935
Common stock issued		0
Common stock issued/sold			423				724
Issuance of parent company stock			66
Stock-based compensation and allocation of ESOP shares			(368)			50
Other			(2)	(25)
Adoption of accounting standards (Note 1)				0	0
Net income (loss) available for Dow Inc.'s common stockholders	$ 465			465
Dividends to stockholders				(1,673)
Dividends to parent				(1,056)
Settlements and transfers related to separation from DowDuPont Inc.	(6)			5,693	0
Other comprehensive income (loss)	1,231				1,231
ESOP shares acquired						0
Treasury stock purchases							0
Ending balance at Dec. 31, 2017	32,701	0	6,553	33,742	(8,591)	(189)	0
Dow Inc.’s stockholders’ equity	31,515
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interests	$ 1,186
Dividends declared per share of common stock	$ 0
Merger impact		0	0				0
Common stock issued		0
Common stock issued/sold			0				0
Issuance of parent company stock			112
Stock-based compensation and allocation of ESOP shares			377			55
Other			0	(19)
Adoption of accounting standards (Note 1)				989	(1,037)
Net income (loss) available for Dow Inc.'s common stockholders	$ 4,641			4,641
Dividends to stockholders				0
Dividends to parent				(3,711)
Settlements and transfers related to separation from DowDuPont Inc.	240			(182)	0
Other comprehensive income (loss)	(257)				(257)
ESOP shares acquired						0
Treasury stock purchases							0
Ending balance at Dec. 31, 2018	33,621	0	7,042	35,460	(9,885)	(134)	0
Dow Inc.’s stockholders’ equity	32,483
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interests	$ 1,138
Dividends declared per share of common stock	$ 2.10
Merger impact		0	0				0
Common stock issued		8
Common stock issued/sold			57				0
Issuance of parent company stock			28
Stock-based compensation and allocation of ESOP shares			235			45
Other			(37)	(14)
Adoption of accounting standards (Note 1)				(151)	0
Net income (loss) available for Dow Inc.'s common stockholders	$ (1,359)			(1,359)
Dividends to stockholders				(1,550)
Dividends to parent				(535)
Settlements and transfers related to separation from DowDuPont Inc.	(1,935)			(14,806)	793
Other comprehensive income (loss)	(1,154)				(1,154)
ESOP shares acquired						(2)
Treasury stock purchases							(500)
Ending balance at Dec. 31, 2019	14,094	$ 8	$ 7,325	$ 17,045	$ (10,246)	$ (91)	$ (500)
Dow Inc.’s stockholders’ equity	13,541
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interests	$ 553