Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 15,793	$ 13,834	$ 30,692	$ 27,064
Cost of sales	12,400	10,761	23,952	20,955
Research and development expenses	407	408	793	827
Selling, general and administrative expenses	748	720	1,499	1,479
Amortization of intangibles	155	157	314	312
Restructuring and asset related charges (credits) - net	98	(12)	263	(13)
Integration and separation costs	231	136	433	245
Equity in earnings of nonconsolidated affiliates	231	54	474	250
Sundry income (expense) - net	5	322	88	(122)
Interest expense and amortization of debt discount	274	226	544	445
Income before income taxes	1,716	1,814	3,456	2,942
Provision for income taxes	406	455	769	668
Net income	1,310	1,359	2,687	2,274
Net income attributable to noncontrolling interests	31	38	66	65
Net income available for The Dow Chemical Company common stockholder	1,279	1,321	2,621	2,209
Depreciation	606	534	1,227	1,112
Capital expenditures	$ 564	$ 795	$ 987	$ 1,549