CONSOLIDATED FINANCIAL STATEMENTS Impact of New Revenue Standard (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories	$ 9,346	$ 8,365	$ 8,376
Other current assets	898	687	627
Total current assets	28,286	27,293	27,244
Deferred income tax assets	1,672	1,757	1,722
Deferred charges and other assets	1,009	872	829
Total other assets	21,811	22,116	22,038
Total assets	80,221	80,067	79,940
Accounts payable - Other	3,939	3,072	3,062
Income taxes payable	736	692	694
Accrued and other current liabilities	3,294	4,075	4,025
Total current liabilities	16,892	14,435	14,377
Other noncurrent obligations	5,930	6,111	5,994
Total other noncurrent liabilities	18,190	18,906	18,789
Retained earnings	29,536	27,982	28,050
The Dow Chemical Company's stockholders' equity	26,865	25,775	25,823
Total equity	28,017	26,961	27,009	$ 29,589	$ 27,229
Liabilities and Equity	80,221	80,067	$ 79,940
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories	24	(11)
Other current assets	(36)	29
Total current assets	(12)	18
Deferred income tax assets	(27)	25
Deferred charges and other assets	(43)	43
Total other assets	(70)	68
Total assets	(82)	86
Accounts payable - Other	(10)	10
Income taxes payable	2	(2)
Accrued and other current liabilities	(19)	50
Total current liabilities	(27)	58
Other noncurrent obligations	(134)	117
Total other noncurrent liabilities	(134)	117
Retained earnings	79	(89)
The Dow Chemical Company's stockholders' equity	79	(89)
Total equity	79	(89)
Liabilities and Equity	(82)	$ 86
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories	9,370
Other current assets	862
Total current assets	28,274
Deferred income tax assets	1,645
Deferred charges and other assets	966
Total other assets	21,741
Total assets	80,139
Accounts payable - Other	3,929
Income taxes payable	738
Accrued and other current liabilities	3,275
Total current liabilities	16,865
Other noncurrent obligations	5,796
Total other noncurrent liabilities	18,056
Retained earnings	29,615
The Dow Chemical Company's stockholders' equity	26,944
Total equity	28,096
Liabilities and Equity	$ 80,139