Long-Term Debt (Senior Secured Revolving Credit Facility) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Debt Instrument [Line Items]
Period a minimum fixed charge coverage is required	30 days
Period the borrowing availability must exceed amount in clause	30 days
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 400,000
Percentage of commitment on borrowing availability	0.375%
Remaining borrowing capacity	383,079
Letters of credit outstanding	16,921
Amounts drawn under the facility limited to accounts receivable, percentage	85.00%
Amounts drawn under the facility limited to eligible inventory, percentage	70.00%
Amounts drawn under the facility limited to lesser of eligible inventory orderly liquidation, percentage	85.00%
Amounts drawn under the facility limited to cash held in an account with the agent	100.00%
Advances on inventory, maximum	325,000
Sub-limit for letters of credit facility	400,000
Minimum [Member] \| Senior Secured Revolving Credit Facility [Member] \| Plus LIBOR [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate	1.75%
Minimum [Member] \| Senior Secured Revolving Credit Facility [Member] \| Plus Base Rate [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate	0.25%
Minimum [Member] \| Debt Covenant [Member] \| Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowing availability compliance requirements for credit facility	12.50%
Fixed charge coverage ratio for debt covenant	1.0
Borrowing availability compliance requirements for credit facility	50,000
Maximum [Member] \| Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Increase in credit facility borrowings	150,000
Maximum [Member] \| Senior Secured Revolving Credit Facility [Member] \| Plus LIBOR [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate	2.25%
Maximum [Member] \| Senior Secured Revolving Credit Facility [Member] \| Plus Base Rate [Member]
Debt Instrument [Line Items]
Percentage added to basis to find interest rate	0.75%
Minimum Increment [Member]
Debt Instrument [Line Items]
Increase in credit facility borrowings	$ 25,000

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The borrowing availability of the line of credit facility, expressed as a percentage of the commitments under the facility, which may trigger additional compliance requirements for the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The calculated fixed charge coverage ratio.

+ References

No definition available.

+ Details

Name:	wlk_FixedChargeCoverageRatio
Namespace Prefix:	wlk_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Letter of credit sub-limit under the revolving credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents a percentage, that when multiplied by the net amount of eligible accounts receivable, becomes a factor used in the calculation to determine the borrowing capacity of the revolving credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents a percentage, that when multiplied by the cash held in account with an agent and subject to a control agreement with that agent, becomes a factor used in the calculation to determine the borrowing capacity of the revolving credit facility.

+ References

No definition available.

+ Details

Name:	wlk_LineOfCreditFacilityLimitedToCashHeldInAccountWithAgentPercentage
Namespace Prefix:	wlk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum amount of eligible inventory that can be attributed to the calculation to determine the borrowing capacity of the revolving credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents a percentage, that when multiplied by the appraised net orderly liquidation value of eligible inventory, becomes a factor used in the calculation to determine the borrowing capacity of the revolving credit facility.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents a percentage, that when multiplied by the value of the lower of cost or market of eligible inventory, becomes a factor used in the calculation to determine the borrowing capacity of the revolving credit facility.

+ References

No definition available.

+ Details

Name:	wlk_LineOfCreditFacilityLimitedToLesserOfEligibleInventoryPercentage
Namespace Prefix:	wlk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Period the Borrowing Availability Must Exceed Amount in Clause

+ References

No definition available.

+ Details

Name:	wlk_LineOfCreditFacilityPeriodBorrowingAvailabilityMustExceedAmountInClause
Namespace Prefix:	wlk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Period a Minimum Fixed Charge Coverage is Required

+ References

No definition available.

+ Details

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Namespace Prefix:	wlk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The permitted amount the line of credit facility may be increased by, under certain circumstances if certain lenders agree to commit to such an increase.

+ References

No definition available.

+ Details

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

- Definition

The minimum allowable borrowing availability under the line of credit facility without potentially triggering additional compliance requirements for the credit facility.

+ References

No definition available.

+ Details

Name:	wlk_MinimumBorrowingAvailability
Namespace Prefix:	wlk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant