v2.4.0.6
Guarantor Disclosures (Condensed Consolidating Financial Information Statement Of Operations) (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2010
Sep. 30, 2010
Jun. 30, 2010
Mar. 31, 2010
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Condensed Financial Statements, Captions [Line Items]                      
Net sales $ 859,175 $ 968,372 $ 925,049 $ 867,252 $ 795,387 $ 779,677 $ 818,389 $ 778,334 $ 3,619,848 [1] $ 3,171,787 [1] $ 2,325,723 [1]
Cost of sales                 3,060,842 2,689,104 2,130,595
Gross profit 77,260 147,067 167,095 167,584 164,124 134,855 126,024 57,680 559,006 482,683 195,128
Selling, general and administrative expenses                 112,210 104,319 87,871
Income from operations 50,459 117,331 138,369 140,637 137,052 107,346 99,537 34,429 446,796 378,364 107,257
Interest expense                 (50,992) (39,875) (34,957)
Other income, (expense), net                 5,628 4,471 6,453
Income before income taxes                 401,432 342,960 78,753
(Benefit from) provision for income taxes                 142,466 121,567 25,758
Equity in net income of subsidiaries                         
Net income 26,443 67,930 81,049 83,544 84,073 [2] 62,731 [2] 56,942 [2] 17,647 [2] 258,966 221,393 52,995
Westlake Chemical Corporation [Member]
                      
Condensed Financial Statements, Captions [Line Items]                      
Net sales                        
Cost of sales                        
Gross profit                        
Selling, general and administrative expenses                 3,762 4,257 4,185
Income from operations                 (3,762) (4,257) (4,185)
Interest expense                 (50,919) (39,829) (34,864)
Other income, (expense), net                 10,217 15,045 14,843
Income before income taxes                 (44,464) (29,041) (24,206)
(Benefit from) provision for income taxes                 (11,835) (2,471) (6,314)
Equity in net income of subsidiaries                 291,595 247,963 70,887
Net income                 258,966 221,393 52,995
Guarantor Subsidiaries [Member]
                      
Condensed Financial Statements, Captions [Line Items]                      
Net sales                 3,581,470 3,130,513 2,289,953
Cost of sales                 3,024,419 2,653,234 2,099,795
Gross profit                 557,051 477,279 190,158
Selling, general and administrative expenses                 102,989 95,441 80,213
Income from operations                 454,062 381,838 109,945
Interest expense                 (73) (46) (93)
Other income, (expense), net                 (4,212) (12,715) (12,981)
Income before income taxes                 449,777 369,077 96,871
(Benefit from) provision for income taxes                 155,313 122,541 31,620
Equity in net income of subsidiaries                         
Net income                 294,464 246,536 65,251
Non-Guarantor Subsidiaries [Member]
                      
Condensed Financial Statements, Captions [Line Items]                      
Net sales                 42,202 44,006 38,980
Cost of sales                 40,247 38,602 34,010
Gross profit                 1,955 5,404 4,970
Selling, general and administrative expenses                 5,459 4,621 3,473
Income from operations                 (3,504) 783 1,497
Interest expense                       
Other income, (expense), net                 (377) 2,141 4,591
Income before income taxes                 (3,881) 2,924 6,088
(Benefit from) provision for income taxes                 (1,012) 1,497 452
Equity in net income of subsidiaries                         
Net income                 (2,869) 1,427 5,636
Eliminations [Member]
                      
Condensed Financial Statements, Captions [Line Items]                      
Net sales                 (3,824) (2,732) (3,210)
Cost of sales                 (3,824) (2,732) (3,210)
Gross profit                        
Selling, general and administrative expenses                        
Income from operations                        
Interest expense                        
Other income, (expense), net                        
Income before income taxes                        
(Benefit from) provision for income taxes                        
Equity in net income of subsidiaries                 (291,595) (247,963) (70,887)
Net income                 $ (291,595) $ (247,963) $ (70,887)
[1] Revenues are attributed to countries based on location of customer.
[2] Basic and diluted earnings per common share ("EPS") for each quarter is computed using the weighted average shares outstanding during that quarter, while EPS for the year is computed using the weighted average shares outstanding for the year. As a result, the sum of the EPS for each of the four quarters may not equal the EPS for the year.