Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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-Name Staff Accounting Bulletin (SAB)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response)

-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

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- Definition

The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1)

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-Name Accounting Standards Codification

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-Section 45

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-Name Staff Accounting Bulletin (SAB)

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- Definition

The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

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- Definition

The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by or used in operations using the indirect method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

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-Publisher FASB

-Name Accounting Standards Codification

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-Name Staff Accounting Bulletin (SAB)

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- Definition

The amount of the write-off for research and development assets that were acquired in a transaction other than a business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

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- Definition

Amount of costs incurred to date for the specified restructuring cost.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

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-Publisher FASB

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

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- Definition

The amount of consideration recognized during the period under a development, licensing and supply agreement entered into with a customer.

+ References

No definition available.

+ Details

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- Definition

This element represents the amount of any change, including any differences arising upon settlement, recognized during the reporting period in the value of the SmartDose contingent consideration liability.

+ References

No definition available.

+ Details

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Other (Income) Expense (Textuals) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013
Restructuring Cost and Reserve [Line Items]
License Cost	$ 1.2	$ 0	$ 0
Development Income	1.6wst_DevelopmentIncome	2.0wst_DevelopmentIncome	6.5wst_DevelopmentIncome
Deferred Revenue				20.0us-gaap_DeferredRevenue
Recognition of income related to nonrefundable payment		1.0us-gaap_RecognitionOfDeferredRevenue
Unearned income, current	1.5us-gaap_DeferredRevenueCurrent
Unearned income, noncurrent	15.9us-gaap_DeferredRevenueNoncurrent
Increase in contingent consideration liability	1.1	1.0	1.2
2010 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges, incurred to date	$ 21.9