Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net trade sales	$ 129	$ 138	$ 136
Net sales to related companies	3,574	4,239	5,310
Total net sales	3,703	4,377	5,446
Cost of sales	3,245	3,500	4,047
Research and development expenses	24	25	21
Selling, general and administrative expenses	9	4	6
Restructuring Charges	15	79	3
Integration and separation costs	0	2	3
Total sundry income (expense) - net	168	(82)	(62)
Interest Income, Other	12	36	28
Interest expense and amortization of debt discount	33	30	30
Income Before Income Taxes	557	691	1,302
Provision (Credit) for income taxes	130	64	247
Net Income Attributable to Union Carbide Corporation	$ 427	$ 627	$ 1,055