Earnings and Dividends per Share (Schedule Of Net Income Attributable To Common Stockholders) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings and Dividends Per Share [Abstract]
Net income attributable to Westlake Corporation	$ 2,015	$ 330	$ 421
Net income attributable to participating securities	(10)	(1)	(2)
Net income attributable to common shareholders	$ 2,005	$ 329	$ 419