Income Taxes (Components Of Income (Loss) Before Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Domestic	$ 1,102,101	$ 944,378	$ 586,631
Foreign	(18,183)	(2,206)	(1,462)
Income before income taxes	$ 1,083,918wlk_IncomeLossBeforeIncomeTaxes	$ 942,172wlk_IncomeLossBeforeIncomeTaxes	$ 585,169wlk_IncomeLossBeforeIncomeTaxes

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

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- 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

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- 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.

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