Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Cash Flows [Abstract]
Net income (loss) attributable to Union Carbide Corporation	$ (49)	$ 146
Depreciation and amortization	51	52
Provision (credit) for deferred income tax	(4)	1
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property	(1)	(1)
Restructuring and asset related charges - net	0	2
Net periodic pension benefit cost	(1)	14
Pension contributions	(547)	(1)
Other Noncash Income	(1)	(1)
Accounts and notes receivable	(6)	1
Related company receivables	594	(48)
Inventories	(34)	4
Accounts payable	19	3
Related company payables	120	(95)
Asbestos-related payments	(18)	(18)
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(58)	53
Cash provided by operating activities	65	112
Capital expenditures	(23)	(33)
Change in noncurrent receivable from related company	(2)	0
Cash used for investing activities	(25)	(33)
Dividends paid to parent	(40)	(81)
Changes in short-term notes payable	0	2
Cash used for financing activities	(40)	(79)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	0	0
Cash and cash equivalents at beginning of period	11	11
Cash and cash equivalents at end of period	$ 11	$ 11