Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) [Member]
Union Carbide Corporation' stockholder's equity, beginning balance at Dec. 31, 2016	$ 1,798	$ 0	$ 138	$ 2,980	$ (1,320)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Union Carbide Corporation	173	0	0	173	0
Other comprehensive income	13	0	0	0	13
Dividends declared	(169)	0	0	(169)	0
Union Carbide Corporation's stockholder's equity, ending balance at Mar. 31, 2017	1,815	0	138	2,984	(1,307)
Union Carbide Corporation' stockholder's equity, beginning balance at Dec. 31, 2017	1,368	0	138	2,582	(1,352)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Union Carbide Corporation	165	0	0	165	0
Other comprehensive income	16	0	0	0	16
Dividends declared	(111)	0	0	(111)	0
Union Carbide Corporation's stockholder's equity, ending balance at Mar. 31, 2018	$ 1,438	$ 0	$ 138	$ 2,636	$ (1,336)