Business and Geographic Regions BUSINESS AND GEOGRAPHIC REGIONS (Sales to External Customers by Principal Product Group) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Sales to external customers	$ 14,811	$ 13,633	$ 13,834	$ 13,230	$ 13,020	$ 12,483	$ 11,952	$ 10,703	$ 55,508	$ 48,158	$ 48,778
Chlorinated Organics [Member]
Sales to external customers									0	0	212
Coatings and Performance Monomers [Member]
Sales to external customers									3,761	3,362	3,857
Construction Chemicals [Member]
Sales to external customers									736	704	709
Consumer Solutions [Member]
Sales to external customers									5,039	3,050	660
Crop Protection [Member]
Sales to external customers									4,553	4,628	4,877
Electronics & Imaging [Member]
Sales to external customers									2,615	2,307	1,987
Energy Solutions [Member]
Sales to external customers									355	354	453
Epoxy [Member]
Sales to external customers									0	0	1,125
Hydrocarbons & Energy [Member]
Sales to external customers									6,831	5,088	4,591
Industrial Biosciences [Member]
Sales to external customers									484	419	437
Industrial Solutions [Member]
Sales to external customers									3,735	3,335	3,805
Nutrition & Health [Member]
Sales to external customers									591	556	592
Packaging and Specialty Plastics [Member]
Sales to external customers									14,110	13,316	13,766
Polyurethanes & CAV [Member]
Sales to external customers									7,804	6,424	7,358
Safety & Construction [Member]
Sales to external customers									1,932	1,877	1,938
Seed [Member]
Sales to external customers									1,393	1,545	1,450
Transportation & Advanced Polymers [Member]
Sales to external customers									1,167	897	583
Corporate, Non-Segment [Member]
Sales to external customers									383	281	349
Other [Member]
Sales to external customers									$ 19	$ 15	$ 29