Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net sales	$ 4,056	$ 2,357
Cost of sales	2,771	1,848
Gross profit	1,285	509
Selling, general and administrative expenses	200	136
Amortization of intangibles	42	27
Restructuring, transaction and integration-related costs	11	0
Income from operations	1,032	346
Other income (expense)
Interest expense	(46)	(33)
Other income, net	11	12
Income before income taxes	997	325
Provision for income taxes	233	72
Net income	764	253
Net income attributable to noncontrolling interests	8	11
Net income attributable to Westlake Corporation	$ 756	$ 242
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 5.87	$ 1.88
Diluted (in dollars per share)	$ 5.83	$ 1.87
Weighted average common shares outstanding:
Basic (in shares)	128,071,355	127,955,532
Diluted (in shares)	128,925,099	128,483,373