ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			$ 39
Accumulated Other Comprehensive Income (Loss) [Line Items]
Union Carbide Corporation's stockholder's equity	$ 1,706	$ 2,478	1,706	$ 2,478	$ 1,798	$ 2,301
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			1	32
Other Comprehensive Income (Loss), Net of Tax	13	11	40	32
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Union Carbide Corporation's stockholder's equity	(1,280)	(1,196)	(1,280)	(1,196)	(1,320)	(1,228)
Other Comprehensive Income (Loss), Net of Tax			40	32
Cumulative translation adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			3
Accumulated Other Comprehensive Income (Loss) [Line Items]
Union Carbide Corporation's stockholder's equity	(58)	(61)	(58)	(61)	(62)	(61)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			1	0
Other Comprehensive Income (Loss), Net of Tax			4	0
Pension and other postretirement benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			36
Accumulated Other Comprehensive Income (Loss) [Line Items]
Union Carbide Corporation's stockholder's equity	(1,222)	(1,135)	(1,222)	(1,135)	$ (1,258)	$ (1,167)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			0	32
Other Comprehensive Income (Loss), Net of Tax			36	32
Other Comprehensive Income (Loss), Tax	6	6	22	20
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	12	11	39	32
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cumulative translation adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Nonoperating Income (Expense)	0	0	3	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and other postretirement benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	18	17	58	52
Reclassification from AOCI, Current Period, Tax	(6)	(6)	(22)	(20)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 12	$ 11	$ 36	$ 32