Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Net sales	$ 3,956	$ 3,055	$ 12,495	$ 8,271
Cost of sales	3,180	2,037	8,989	5,872
Gross profit	776	1,018	3,506	2,399
Selling, general and administrative expenses	215	122	635	383
Amortization of intangibles	39	29	124	83
Restructuring, transaction and integration-related costs	6	6	24	6
Income from operations	516	861	2,723	1,927
Other income (expense)
Interest expense	(44)	(61)	(134)	(130)
Other income, net	24	13	52	35
Income before income taxes	496	813	2,641	1,832
Provision for income taxes	84	193	592	423
Net income	412	620	2,049	1,409
Net income attributable to noncontrolling interests	11	13	34	38
Net income attributable to Westlake Corporation	$ 401	$ 607	$ 2,015	$ 1,371
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 3.12	$ 4.71	$ 15.65	$ 10.65
Diluted (in dollars per share)	$ 3.10	$ 4.69	$ 15.54	$ 10.60
Weighted average common shares outstanding:
Basic (in shares)	127,943,400	128,060,193	128,118,160	128,053,337
Diluted (in shares)	128,747,012	128,765,814	129,003,750	128,710,097