RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Dividends declared			$ (500)
The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Service Fee with Parent	10.00%
Notes Receivable, Related Parties	$ 1,300	$ 1,200
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Notes Receivable, Related Parties, Noncurrent	949	949
Dividends declared	(553)	(603)
General and Administrative Expense [Member] \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	30	33	27
Estimated Federal Tax Liability, Related Party [Member] \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Tax Payment	220	294	415
Purchases from Dow [Member] \| Cost of Sales [Member] \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	1,600	1,700	1,400
Activity Based Costs [Member] \| Cost of Sales [Member] \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 85	$ 78	$ 58

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