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RELATD PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
RELATD PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Short-term Debt	$ 517			$ 517		$ 298
The Dow Chemical Company [Domain] \| DowDuPont [Member]
Cash Dividends Paid to DowDuPont		$ 535	$ 1,048		$ 3,158
Accounts Receivable, Related Parties, Current						89
The Dow Chemical Company [Domain] \| DuPont and its Affiliates [Member]
Net sales	0		16	12	41
Related Party Costs	0		$ 12	9	$ 32
The Dow Chemical Company [Domain] \| Accounts and notes receivable - Other \| DuPont and its Affiliates [Member]
Related Party Transaction, Due from (to) Related Party	0			0		89
The Dow Chemical Company [Domain] \| Accounts payable - Other \| DuPont and its Affiliates [Member]
Related Party Transaction, Due from (to) Related Party	0			0		19
Notes Payable to Related Party [Member]
Short-term Debt	76			76		$ 0
Notes Payable to Related Party [Member] \| The Dow Chemical Company [Domain] \| Dow Inc. [Member]
Short-term Debt	$ 418			$ 418