SUPPLEMENTARY INFORMATION (Sundry Income, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplementary Information [Line Items]
Net gain on sales of property	$ 0	$ 23	$ 50
Interest income	28	20	14
Non-operating pension and other postretirement benefit plan net credits (costs)	(1)	8	11
Net gain on sale of a nonconsolidated affiliate	0	4	0
Foreign exchange gain	0	0	1
Other - net	(9)	(3)	0
Total sundry income (expense) - net	(34)	(3)	27
Administrative and overhead fees [Member] | The Dow Chemical Company [Member]
Supplementary Information [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	(30)	(33)	(27)
Net Commission Expense [Member]
Supplementary Information [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ (22)	$ (22)	$ (22)