Subsequent Events Subsequent Events (Details) (Subsequent Event [Member], Limited Partner [Member], USD $)	0 Months Ended
Apr. 29, 2015
Westlake Chemical OpCo LP [Member]
Subsequent Event [Line Items]
Partnership's ownership interest	86.70%
Westlake Chemical Partners LP [Member] \| Subsidiary of Common Parent [Member] \| Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Maximum borrowing capacity	300,000,000
Westlake Chemical Partners LP [Member] \| Westlake Chemical OpCo LP [Member]
Subsequent Event [Line Items]
Additional limited partner interest purchased	2.70%
Amount paid to purchase additional limited partner interest	135,341,000
Partnership's ownership interest	13.30%

The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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- 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

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- Definition

Cash outflow related to the acquisition or continued holding of limited partnership interests held for investment purposes.

+ References

No definition available.

+ Details

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- Definition

Limited Partnership Ownership Percentage Increase

+ References

No definition available.

+ Details

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Balance Type:	na
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