Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Net sales	$ 2,975	$ 3,356
Cost of sales	2,509	2,564
Gross profit	466	792
Selling, general and administrative expenses	209	222
Amortization of intangibles	30	31
Restructuring, transaction and integration-related costs	4	3
Income from operations	223	536
Other income (expense)
Interest expense	(40)	(42)
Other income, net	50	22
Income before income taxes	233	516
Provision for income taxes	48	109
Net income	185	407
Net income attributable to noncontrolling interests	11	13
Net income attributable to Westlake Corporation	$ 174	$ 394
Earnings per common share attributable to Westlake Corporation:
Basic (in dollars per share)	$ 1.35	$ 3.07
Diluted (in dollars per share)	$ 1.34	$ 3.05
Weighted average common shares outstanding:
Basic (in shares)	128,359,983	127,548,287
Diluted (in shares)	129,020,370	128,459,368