Earnings and Dividends per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic	128,359,983	127,548,287
Weighted Average Number Diluted Shares Outstanding Adjustment	660,387	911,081
Weighted average common shares-diluted	129,020,370	128,459,368
Earnings per share attributable to Westlake Corporation: Basic (in dollars per share)	$ 1.35	$ 3.07
Earnings per share attributable to Westlake Corporation: Diluted (in dollars per share)	$ 1.34	$ 3.05