Collaboration and Other Agreements - Collaboration Services and Milestone Revenue (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration services and other revenue	$ 4,089,000	$ 3,198,000
License and milestone revenue	0pcyc_LicenseAndMilestoneRevenue	60,000,000pcyc_LicenseAndMilestoneRevenue
Total revenue	205,772,000us-gaap_Revenues	119,377,000us-gaap_Revenues
Deferred revenue, noncurrent	32,757,000us-gaap_DeferredRevenueNoncurrent		34,885,000us-gaap_DeferredRevenueNoncurrent
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
milestone revenue recognized		60,000,000
Deferred revenue	43,900,000
Deferred revenue, noncurrent	32,800,000
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration services and other revenue	4,089,000	3,135,000
License and milestone revenue	0	60,000,000
Total revenue	$ 4,089,000	$ 63,135,000

Collaboration Service and Other Revenue

No definition available.

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- Definition

License and milestone revenue related to collaboration and license arrangements.

+ References

No definition available.

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- Definition

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.

+ References

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

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

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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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

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

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-Name Accounting Standards Codification

-Topic 210

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-Paragraph 8

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

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- Definition

The amount of consideration recognized during the period for the milestone or milestones.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 28

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=19771982&loc=SL6892177-166501

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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