Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income attributable to Union Carbide Corporation	$ 65	$ 68	$ 16	$ 214
Cumulative translation adjustments	0	0	0	3
Pension and other postretirement benefit plans	20	19	104	39
Total other comprehensive income	20	19	104	42
Comprehensive income attributable to Union Carbide Corporation	$ 85	$ 87	$ 120	$ 256