Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accum. Other Comp Loss
Beginning balance at Dec. 31, 2015	$ 2,301	$ 0	$ 138	$ 3,391	$ (1,228)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Union Carbide Corporation	89			89
Other comprehensive income (loss)	(92)				(92)
Dividends declared	(500)			(500)
Ending 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	205			205
Other comprehensive income (loss)	(32)				(32)
Dividends declared				(603)
Ending 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	1,055			1,055
Other comprehensive income (loss)	45				45
Dividends declared				(553)
Ending balance at Dec. 31, 2018	1,915	$ 0	$ 138	3,338	(1,561)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of accounting standard (Note 1)	$ 0			$ 254	$ (254)