Consolidated Statements Of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 5,075,456	$ 4,463,336	$ 4,415,350
Cost of sales	4,094,894	3,278,145	3,098,000
Gross profit	980,562	1,185,191	1,317,350
Selling, general and administrative expenses	295,436	225,364	183,745
Transaction and integration-related costs	103,672	0	9,614
Income from operations	581,454	959,827	1,123,991
Other income (expense)
Interest expense	(79,473)	(34,656)	(37,352)
Other income (expense), net	56,398	38,270	(2,721)
Income before income taxes	558,379	963,441	1,083,918
Provision for income taxes	138,520	298,396	398,902
Net income	419,859	665,045	685,016
Net income attributable to noncontrolling interests	21,000	19,035	6,493
Net income attributable to Westlake Chemical Corporation	$ 398,859	$ 646,010	$ 678,523
Earnings per common share attributable to Westlake Chemical Corporation (Note 18):
Basic (in dollars per share)	$ 3.07	$ 4.88	$ 5.09
Diluted (in dollars per share)	$ 3.06	$ 4.86	$ 5.07
Weighted average shares outstanding (Note 18)
Basic (in shares)	129,367,712	131,823,707	133,111,230
Diluted (in shares)	129,974,822	132,301,812	133,643,414
Dividends per common share (Note 11) (in dollars per share)	$ 0.7442	$ 0.6930	$ 0.5820