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]	Noncontrolling Interests
Total Equity, Beginning at Dec. 31, 2017		$ 0	$ 6,553	$ 28,050	$ (8,591)	$ (189)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of parent company stock			63
Stock-based compensation and allocation of ESOP shares			142			39
Net income available for The Dow Chemical Company common stockholder				1,342
Dividends to parent				(1,057)
Other				(6)
Other comprehensive income	$ 483				483
Total Equity, Ending at Mar. 31, 2018	27,971	0	6,758	28,261	(8,088)	(150)	$ 1,190
Stockholders' Equity Attributable to Parent	26,781
Stockholders' Equity Attributable to Parent	26,831
Total Equity, Beginning at Dec. 31, 2018	27,969	0	7,042	29,808	(9,885)	(134)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of parent company stock			28
Stock-based compensation and allocation of ESOP shares			83			29
Net income available for The Dow Chemical Company common stockholder				541
Dividends to parent				(535)
Other				(2)
Other comprehensive income	102				102
Total Equity, Ending at Mar. 31, 2019	28,146	$ 0	$ 7,153	$ 29,701	$ (9,783)	$ (105)	$ 1,180
Stockholders' Equity Attributable to Parent	$ 26,966