Guarantor Disclosures (Condensed Consolidating Financial Information Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 951,625	$ 1,004,165	$ 939,047	$ 864,647	$ 801,041	$ 821,175	$ 913,958	$ 1,034,867	$ 3,759,484	[1]	$ 3,571,041	[1]	$ 3,619,848	[1]
Cost of sales									2,658,046		2,834,081		3,060,842
Gross profit	295,671	304,471	273,487	227,809	190,248	172,179	201,896	172,637	1,101,438		736,960		559,006
Selling, general and administrative expenses									147,974		121,609		112,210
Income from operations	257,580	266,602	235,227	194,055	156,231	142,517	170,978	145,625	953,464		615,351		446,796
Interest expense									(18,082)		(43,049)		(50,992)
Debt retirement costs									0		(7,082)		0
Gain from sales of equity securities									0		16,429		0
Other income, (expense), net									6,790		3,520		5,628
Income before income taxes									942,172		585,169		401,432
(Benefit from) provision for income taxes									331,747		199,614		142,466
Equity in net income of subsidiaries									0		0		0
Net income	170,972	170,290	145,816	123,347	95,277	86,964	115,501	87,813	610,425		385,555		258,966
Comprehensive income									618,649		383,785		256,929
Westlake Chemical Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									0		0		0
Cost of sales									0		0		0
Gross profit									0		0		0
Selling, general and administrative expenses									2,128		2,004		3,762
Income from operations									(2,128)		(2,004)		(3,762)
Interest expense									(18,030)		(42,989)		(50,919)
Debt retirement costs											(7,082)
Gain from sales of equity securities											1
Other income, (expense), net									11,798		28,171		10,217
Income before income taxes									(8,360)		(23,903)		(44,464)
(Benefit from) provision for income taxes									(2,031)		1,825		(11,835)
Equity in net income of subsidiaries									616,754		411,283		291,595
Net income									610,425		385,555		258,966
Comprehensive income									618,649		383,785		256,929
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									3,720,110		3,529,685		3,581,470
Cost of sales									2,623,355		2,799,537		3,024,419
Gross profit									1,096,755		730,148		557,051
Selling, general and administrative expenses									139,662		113,133		102,989
Income from operations									957,093		617,015		454,062
Interest expense									(52)		(60)		(73)
Debt retirement costs											0
Gain from sales of equity securities											16,428
Other income, (expense), net									(2,769)		(21,384)		(4,212)
Income before income taxes									954,272		611,999		449,777
(Benefit from) provision for income taxes									334,619		199,057		155,313
Equity in net income of subsidiaries									0		0
Net income									619,653		412,942		294,464
Comprehensive income									629,308		410,549		292,834
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									48,016		48,205		42,202
Cost of sales									43,333		41,393		40,247
Gross profit									4,683		6,812		1,955
Selling, general and administrative expenses									6,184		6,472		5,459
Income from operations									(1,501)		340		(3,504)
Interest expense									0		0		0
Debt retirement costs											0
Gain from sales of equity securities											0
Other income, (expense), net									(2,239)		(3,267)		(377)
Income before income taxes									(3,740)		(2,927)		(3,881)
(Benefit from) provision for income taxes									(841)		(1,268)		(1,012)
Equity in net income of subsidiaries									0		0
Net income									(2,899)		(1,659)		(2,869)
Comprehensive income									(4,506)		(1,036)		(3,276)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									(8,642)		(6,849)		(3,824)
Cost of sales									(8,642)		(6,849)		(3,824)
Gross profit									0		0		0
Selling, general and administrative expenses									0		0		0
Income from operations									0		0		0
Interest expense									0		0		0
Debt retirement costs											0
Gain from sales of equity securities											0
Other income, (expense), net									0		0		0
Income before income taxes									0		0		0
(Benefit from) provision for income taxes									0		0		0
Equity in net income of subsidiaries									(616,754)		(411,283)		(291,595)
Net income									(616,754)		(411,283)		(291,595)
Comprehensive income									$ (624,802)		$ (409,513)		$ (289,558)

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