Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 307	$ 873	$ 714	$ 1,637
Other comprehensive income (loss), net of income taxes
Pension and other post-retirement benefits reserves adjustment	0	1	0	1
Income tax provision on pension and other post-retirement benefits liability	(13)	0	(13)	0
Foreign currency translation adjustments
Foreign currency translation	(1)	(61)	19	(69)
Income tax (provision) benefit on foreign currency translation	2	(13)	5	(16)
Other, net of income tax	0	0	(1)	0
Other comprehensive income (loss), net of income taxes	(12)	(73)	10	(84)
Comprehensive income	295	800	724	1,553
Comprehensive income attributable to noncontrolling interests, net of tax of $1 and $1 for the three months ended June 30, 2023 and 2022; and net of tax of $2 and $2 for the six months ended June 30, 2023 and 2022, respectively	10	13	23	19
Comprehensive income attributable to Westlake Corporation	$ 285	$ 787	$ 701	$ 1,534