Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 462	$ 1,034	$ 1,339
Pension and other post-retirement benefits
Pension and other post-retirement benefits reserves adjustment	(32)	(33)	19
Amortization of benefits liability	0	0	2
Income tax benefit (provision) on pension and other post-retirement benefits	8	8	(7)
Foreign Currency Translation Adjustment
Foreign currency translation	17	(59)	124
Income tax provision on foreign currency translation	(4)	0	(5)
Other comprehensive income (loss), net of income taxes	(11)	(84)	133
Comprehensive income	451	950	1,472
Comprehensive income attributable to noncontrolling interests, net of tax of $2, $4 and $1 for 2019, 2018 and 2017, respectively	42	36	40
Comprehensive income attributable to Westlake Chemical Corporation	$ 409	$ 914	$ 1,432