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RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2026	Jun. 30, 2025
Related Party Transaction [Line Items]
Cost of sales	$ 1,051	$ 1,063		$ 2,119	$ 2,127
Sundry income (expense) - net	(31)	(31)		(60)	(61)
Short-term Lease Cost	12	18		27	34
Payments of Dividends				0	28
Investment Income, Dividend			$ 4
The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Short-term Lease Cost	3	3		7	7
Payments of Dividends	0	0		0	28
Activity Based Costs \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Cost of sales	167	181		359	362
Commodity And Raw Material Purchases \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Cost of sales	294	251		548	516
Net Commission Expense \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Sundry income (expense) - net	5	5		10	9
General administrative and overhead type services and service fee \| The Dow Chemical Company [Member]
Related Party Transaction [Line Items]
Sundry income (expense) - net	$ 11	$ 17		$ 21	$ 36