Consolidated Statements of Equity - USD ($) $ in Millions	Total	Union Carbide Corporation's Stockholder's Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss), Net of Tax [Member]
Stock Repurchased and Retired During Period, Value	$ 174
Balance at beginning of year at Dec. 31, 2014			$ 0	$ 312	$ 3,740	$ (1,243)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Union Carbide Corporation	588				588
Dividends declared					(220)
Stockholders' Equity, Other					14
Other Comprehensive Income (Loss), Net of Tax						38
Balance at end of period at Sep. 30, 2015			0	138	4,122	(1,205)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 3,055
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,301
Stock Repurchased and Retired During Period, Value	0
Balance at beginning of year at Dec. 31, 2015			0	138	3,391	(1,228)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Union Carbide Corporation	599				599
Dividends declared					(455)
Stockholders' Equity, Other					1
Other Comprehensive Income (Loss), Net of Tax						32
Balance at end of period at Sep. 30, 2016			$ 0	$ 138	$ 3,536	$ (1,196)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,478	$ 2,478