Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Statement [Abstract]
Net sales	$ 4,415,350	[1]	$ 3,759,484	[1]	$ 3,571,041	[1]
Cost of sales	3,098,000		2,658,046		2,834,081
Gross profit	1,317,350		1,101,438		736,960
Selling, general and administrative expenses	193,359		147,974		121,609
Income from operations	1,123,991		953,464		615,351
Other income (expense)
Interest expense	(37,352)		(18,082)		(43,049)
Debt retirement costs	0		0		(7,082)
Gain from sales of equity securities	0		0		16,429
Other (expense) income, net	(2,721)		6,790		3,520
Income before income taxes	1,083,918		942,172		585,169
Provision for income taxes	398,902		331,747		199,614
Net income	685,016		610,425		385,555
Net income attributable to noncontrolling interests	6,493		0		0
Net income attributable to Westlake Chemical Corporation	$ 678,523		$ 610,425		$ 385,555
Earnings per common share attributable to Westlake Chemical Corporation (Note 8):
Basic	$ 5.09		$ 4.57		$ 2.89
Diluted	$ 5.07		$ 4.55		$ 2.88
Weighted average shares outstanding (Note 8):
Basic	133,111,230		133,224,256		132,578,858
Diluted	133,643,414		133,779,250		133,282,990
Dividends per common share	$ 0.5820		$ 0.4125		$ 2.1363

[1] Revenues are attributed to countries based on location of customer.