Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income attributable to Union Carbide Corporation	$ 86	$ 119	$ 298	$ 475
Cumulative translation adjustments	0	0	2	0
Pension and other postretirement benefit plans	9	19	28	57
Total other comprehensive income	9	19	30	57
Comprehensive income attributable to Union Carbide Corporation	$ 95	$ 138	$ 328	$ 532