Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 764	$ 253
Foreign currency translation adjustments
Foreign currency translation	(8)	3
Income tax provision on foreign currency translation	(3)	(10)
Other comprehensive income (loss), net of income taxes	(11)	(7)
Comprehensive income	753	246
Comprehensive income attributable to noncontrolling interests, net of tax of $1 and $0 for the three months ended March 31, 2022 and 2021, respectively	6	10
Comprehensive income attributable to Westlake Corporation	$ 747	$ 236