Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Net sales	$ 4,483	$ 2,859	$ 8,539	$ 5,216
Cost of sales	3,038	1,987	5,809	3,835
Gross profit	1,445	872	2,730	1,381
Selling, general and administrative expenses	220	125	420	261
Amortization of intangibles	43	27	85	54
Restructuring, transaction and integration-related costs	7	0	18	0
Income from operations	1,175	720	2,207	1,066
Other income (expense)
Interest expense	(44)	(36)	(90)	(69)
Other income, net	17	10	28	22
Income before income taxes	1,148	694	2,145	1,019
Provision for income taxes	275	158	508	230
Net income	873	536	1,637	789
Net income attributable to noncontrolling interests	15	14	23	25
Net income attributable to Westlake Corporation	$ 858	$ 522	$ 1,614	$ 764
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 6.65	$ 4.06	$ 12.52	$ 5.94
Diluted (in dollars per share)	$ 6.60	$ 4.04	$ 12.43	$ 5.91
Weighted average common shares outstanding:
Basic (in shares)	128,341,132	128,142,997	128,206,988	128,049,852
Diluted (in shares)	129,341,096	128,877,860	129,134,246	128,681,776