COMMITMENTS AND CONTINGENT LIABILITIES (Environmental Matters) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 1,193	$ 1,193	$ 810
Accrual for Environmental Loss Contingencies, Revision in Estimates	399	399
Accrual For Environmental Loss Contingencies Superfund Sites [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	211	211	156
Dow Silicones Corporation [Member]
Loss Contingencies [Line Items]
Indemnification Asset	100	100	$ 0
Packaging & Specialty Plastics [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates	5	5
Industrial Intermediates & Infrastructure [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates	8	8
Performance Materials & Coatings [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates	50	50
Corporation [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates	336
Environmental Issue [Member] | Dow Silicones Corporation [Member]
Loss Contingencies [Line Items]
Indemnification Asset	$ 48	$ 48