Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net sales	$ 3,356	$ 4,056
Cost of sales	2,564	2,771
Gross profit	792	1,285
Selling, general and administrative expenses	222	200
Amortization of intangibles	31	42
Restructuring, transaction and integration-related costs	3	11
Income from operations	536	1,032
Other income (expense)
Interest expense	(42)	(46)
Other income, net	22	11
Income before income taxes	516	997
Provision for income taxes	109	233
Net income	407	764
Net income attributable to noncontrolling interests	13	8
Net income attributable to Westlake Corporation	$ 394	$ 756
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 3.07	$ 5.87
Diluted (in dollars per share)	$ 3.05	$ 5.83
Weighted average common shares outstanding:
Basic (in shares)	127,548,287	128,071,355
Diluted (in shares)	128,459,368	128,925,099