Guarantor Disclosures (Condensed Consolidating Financial Information Statement Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net income	$ 610,425	$ 385,555	$ 258,966
Depreciation and amortization	159,267	146,055	133,080
Deferred income taxes	93,732	(5,793)	14,114
Net changes in working capital and other	(110,695)	86,270	(47,225)
Net cash provided by operating activities	752,729	612,087	358,935
Additions to property, plant and equipment	(679,222)	(386,882)	(176,843)
Construction of assets pending sale-leaseback	(136)	(4,308)	0
Acquisition of business	(178,309)	0	0
Payments to Acquire Equity Method Investments	(23,338)	0	0
Proceeds from disposition of assets	151	471	2,880
Proceeds from repayment of loan to affiliate	167	1,192	1,192
Proceeds from sale-leaseback of assets	0	2,304	0
Proceeds from sales and maturities of equity securities	252,519	47,655
Purchase of securities and other investments	(367,150)	(127,834)	(30,265)
Settlements of derivative instruments	(6,920)	431	251
Net cash used for investing activities	(1,002,238)	(466,971)	(202,785)
Intercompany financing	0	0	0
Capitalized debt issuance costs	0	(2,221)	(2,697)
Dividends paid	(55,236)	(285,521)	(18,265)
Proceeds from debt issuance	0	248,818	0
Proceeds from exercise of stock options	3,437	10,369	5,344
Repayment of debt	0	(250,000)	0
Repurchase of common stock for treasury	(32,918)	(10,784)	(2,518)
Utilization of restricted cash	0	96,433	54,227
Windfall tax benefits from share-based payment arrangements	5,449	11,967	3,361
Net cash (used for) provided by financing activities	(79,268)	(180,939)	39,452
Net (decrease) increase in cash and cash equivalents	(328,777)	(35,823)	195,602
Cash and cash equivalents at beginning of the year	790,078	825,901	630,299
Cash and cash equivalents at end of the year	461,301	790,078	825,901
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	610,425	385,555	258,966
Depreciation and amortization	1,459	1,514	1,683
Deferred income taxes	74	45	190
Net changes in working capital and other	(622,194)	(422,199)	(295,027)
Net cash provided by operating activities	(10,236)	(35,085)	(34,188)
Additions to property, plant and equipment	0	0	0
Construction of assets pending sale-leaseback	0	0
Acquisition of business	0
Payments to Acquire Equity Method Investments	0
Proceeds from disposition of assets	0	0	0
Proceeds from repayment of loan to affiliate	0	0	0
Proceeds from sale-leaseback of assets		0
Proceeds from sales and maturities of equity securities	252,519	3
Purchase of securities and other investments	(367,150)	(124,873)	0
Settlements of derivative instruments	0	0	0
Net cash used for investing activities	(114,631)	(124,870)	0
Intercompany financing	(128,798)	291,455	186,898
Capitalized debt issuance costs		(2,221)	(2,697)
Dividends paid	(55,236)	(285,521)	(18,265)
Proceeds from debt issuance		248,818
Proceeds from exercise of stock options	3,437	10,369	5,344
Repayment of debt		(250,000)
Repurchase of common stock for treasury	(32,918)	(10,784)	(2,518)
Utilization of restricted cash		96,433	54,227
Windfall tax benefits from share-based payment arrangements	5,449	11,967	3,361
Net cash (used for) provided by financing activities	(208,066)	110,516	226,350
Net (decrease) increase in cash and cash equivalents	(332,933)	(49,439)	192,162
Cash and cash equivalents at beginning of the year	753,881	803,320	611,158
Cash and cash equivalents at end of the year	420,948	753,881	803,320
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	619,653	412,942	294,464
Depreciation and amortization	155,360	141,388	127,807
Deferred income taxes	93,841	(5,962)	14,225
Net changes in working capital and other	(115,041)	94,930	(45,667)
Net cash provided by operating activities	753,813	643,298	390,829
Additions to property, plant and equipment	(676,668)	(385,919)	(175,706)
Construction of assets pending sale-leaseback	(136)	(4,308)
Acquisition of business	(178,309)
Payments to Acquire Equity Method Investments	(23,338)
Proceeds from disposition of assets	75	449	2,877
Proceeds from repayment of loan to affiliate	0	0	0
Proceeds from sale-leaseback of assets		2,304
Proceeds from sales and maturities of equity securities	0	47,652
Purchase of securities and other investments	0	(2,961)	(30,265)
Settlements of derivative instruments	(6,920)	431	251
Net cash used for investing activities	(885,296)	(342,352)	(202,843)
Intercompany financing	130,737	(296,490)	(185,522)
Capitalized debt issuance costs		0	0
Dividends paid	0	0	0
Proceeds from debt issuance		0
Proceeds from exercise of stock options	0	0	0
Repayment of debt		0
Repurchase of common stock for treasury	0	0	0
Utilization of restricted cash		0	0
Windfall tax benefits from share-based payment arrangements	0	0	0
Net cash (used for) provided by financing activities	130,737	(296,490)	(185,522)
Net (decrease) increase in cash and cash equivalents	(746)	4,456	2,464
Cash and cash equivalents at beginning of the year	6,973	2,517	53
Cash and cash equivalents at end of the year	6,227	6,973	2,517
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	(2,899)	(1,659)	(2,869)
Depreciation and amortization	2,448	3,153	3,590
Deferred income taxes	(183)	124	(301)
Net changes in working capital and other	9,786	2,256	1,874
Net cash provided by operating activities	9,152	3,874	2,294
Additions to property, plant and equipment	(2,554)	(963)	(1,137)
Construction of assets pending sale-leaseback	0	0
Acquisition of business	0
Payments to Acquire Equity Method Investments	0
Proceeds from disposition of assets	76	22	3
Proceeds from repayment of loan to affiliate	167	1,192	1,192
Proceeds from sale-leaseback of assets		0
Proceeds from sales and maturities of equity securities	0	0
Purchase of securities and other investments	0	0	0
Settlements of derivative instruments	0	0	0
Net cash used for investing activities	(2,311)	251	58
Intercompany financing	(1,939)	5,035	(1,376)
Capitalized debt issuance costs		0	0
Dividends paid	0	0	0
Proceeds from debt issuance		0
Proceeds from exercise of stock options	0	0	0
Repayment of debt		0
Repurchase of common stock for treasury	0	0	0
Utilization of restricted cash		0	0
Windfall tax benefits from share-based payment arrangements	0	0	0
Net cash (used for) provided by financing activities	(1,939)	5,035	(1,376)
Net (decrease) increase in cash and cash equivalents	4,902	9,160	976
Cash and cash equivalents at beginning of the year	29,224	20,064	19,088
Cash and cash equivalents at end of the year	34,126	29,224	20,064
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	(616,754)	(411,283)	(291,595)
Depreciation and amortization	0	0	0
Deferred income taxes	0	0	0
Net changes in working capital and other	616,754	411,283	291,595
Net cash provided by operating activities	0	0	0
Additions to property, plant and equipment	0	0	0
Construction of assets pending sale-leaseback	0	0
Acquisition of business	0
Payments to Acquire Equity Method Investments	0
Proceeds from disposition of assets	0	0	0
Proceeds from repayment of loan to affiliate	0	0	0
Proceeds from sale-leaseback of assets		0
Proceeds from sales and maturities of equity securities	0	0
Purchase of securities and other investments	0	0	0
Settlements of derivative instruments	0	0	0
Net cash used for investing activities	0	0	0
Intercompany financing			0
Capitalized debt issuance costs		0	0
Dividends paid	0	0	0
Proceeds from debt issuance		0
Proceeds from exercise of stock options	0	0	0
Repayment of debt		0
Repurchase of common stock for treasury	0	0	0
Utilization of restricted cash		0	0
Windfall tax benefits from share-based payment arrangements	0	0	0
Net cash (used for) provided by financing activities	0	0	0
Net (decrease) increase in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of the year	0	0	0
Cash and cash equivalents at end of the year	$ 0	$ 0	$ 0