Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Domestic	$ 880,044	$ 1,102,101	$ 944,378
Foreign	83,397	(18,183)	(2,206)
Income before income taxes	$ 963,441	$ 1,083,918	$ 942,172

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

+ References

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_IncomeTaxDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Income or loss from continuing operations, including the portion attributable to noncontrolling interest, and income or loss from equity method investments, but before extraordinary items, cumulative effects of changes in accounting principles and income taxes.

+ References

No definition available.

+ Details

Name:	wlk_IncomeLossBeforeIncomeTaxes
Namespace Prefix:	wlk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration