Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Union Carbide Corporation's Stockholder's Equity at Dec. 31, 2017				$ 2,582	$ (1,352)
Net income attributable to Union Carbide Corporation	$ 471			471
Dividends, Common Stock				(246)
Other Comprehensive Income (Loss), Net of Tax	34				34
Union Carbide Corporation's Stockholder's Equity at Jun. 30, 2018	1,627	$ 0	$ 138	3,061	(1,572)
Stockholders' Equity, Other				0
Union Carbide Corporation's Stockholder's Equity at Mar. 31, 2018				2,636	(1,336)
Net income attributable to Union Carbide Corporation	306			306
Dividends, Common Stock				(135)
Other Comprehensive Income (Loss), Net of Tax	18				18
Union Carbide Corporation's Stockholder's Equity at Jun. 30, 2018	1,627	0	138	3,061	(1,572)
Stockholders' Equity, Other				0
Cumulative Effect of New Accounting Principle in Period of Adoption				254	(254)
Union Carbide Corporation's Stockholder's Equity at Dec. 31, 2018	1,915			3,338	(1,561)
Net income attributable to Union Carbide Corporation	355			355
Dividends, Common Stock				(810)
Other Comprehensive Income (Loss), Net of Tax	29				29
Union Carbide Corporation's Stockholder's Equity at Jun. 30, 2019	1,488	0	138	2,882	(1,532)
Stockholders' Equity, Other				(1)
Union Carbide Corporation's Stockholder's Equity at Mar. 31, 2019				2,951	(1,546)
Net income attributable to Union Carbide Corporation	110			110
Dividends, Common Stock				(178)
Other Comprehensive Income (Loss), Net of Tax	14				14
Union Carbide Corporation's Stockholder's Equity at Jun. 30, 2019	$ 1,488	$ 0	$ 138	2,882	(1,532)
Stockholders' Equity, Other				(1)
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 0	$ 0