Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net sales	$ 1,103,531us-gaap_SalesRevenueNet	$ 1,027,676us-gaap_SalesRevenueNet
Cost of sales	818,985us-gaap_CostOfGoodsSold	740,666us-gaap_CostOfGoodsSold
Gross profit	284,546us-gaap_GrossProfit	287,010us-gaap_GrossProfit
Selling, general and administrative expenses	55,266	38,955
Income from operations	229,280us-gaap_OperatingIncomeLoss	248,055us-gaap_OperatingIncomeLoss
Other income (expense)
Interest expense	(9,591)us-gaap_InterestExpense	(9,157)us-gaap_InterestExpense
Other income, net	9,096us-gaap_NonoperatingIncomeExpense	2,509us-gaap_NonoperatingIncomeExpense
Income before income taxes	228,785	241,407
Provision for income taxes	78,378us-gaap_IncomeTaxExpenseBenefit	83,375us-gaap_IncomeTaxExpenseBenefit
Net income	150,407us-gaap_ProfitLoss	158,032us-gaap_ProfitLoss
Net income attributable to noncontrolling interests	4,065	0
Net income attributable to Westlake Chemical Corporation	$ 146,342us-gaap_NetIncomeLoss	$ 158,032us-gaap_NetIncomeLoss
Earnings per common share attributable to Westlake Chemical Corporation
Basic	$ 1.10us-gaap_EarningsPerShareBasic	$ 1.18us-gaap_EarningsPerShareBasic
Diluted	$ 1.10us-gaap_EarningsPerShareDiluted	$ 1.18us-gaap_EarningsPerShareDiluted
Weighted average shares outstanding:
Basic	132,714,566	133,072,254
Diluted	133,205,306	133,612,924
Dividends per common share	$ 0.1650	$ 0.1260

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770