Earnings and Dividends per Share (Reconciliation of Denominator for Basic and Diluted Earnings Per Share) (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings and Dividends Per Share [Abstract]
Weighted average common shares—basic	127,649,341	128,341,132	127,599,093	128,206,988
Weighted Average Number Diluted Shares Outstanding Adjustment	834,675	999,964	872,667	927,258
Weighted average common shares-diluted	128,484,016	129,341,096	128,471,760	129,134,246
Earnings per share attributable to Westlake Corporation: Basic (in dollars per share)	$ 2.32	$ 6.65	$ 5.39	$ 12.52
Earnings per share attributable to Westlake Corporation: Diluted (in dollars per share)	$ 2.31	$ 6.60	$ 5.35	$ 12.43