Contingent payments receivable based on development events.

No definition available.

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Period Type:	instant

- Definition

Estimated sales consideration on basis of relative selling price method.

+ References

No definition available.

+ Details

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- Definition

License and collaboration agreements potential payments for development milestones.

+ References

No definition available.

+ Details

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Namespace Prefix:	nktr_
Data Type:	xbrli:monetaryItemType
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- Details

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- Definition

Performance milestone used to reimburse clinical trial costs.

+ References

No definition available.

+ Details

Name:	nktr_PerformanceMilestoneUsedToReimburseClinicalTrialCosts
Namespace Prefix:	nktr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Substantive milestone revenue.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- 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

-Paragraph 1

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

-URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date 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

-Paragraph 1

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

-URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780

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- Definition

Revenue earned during the period relating to consideration received from another party for the right to use, but not own, certain of the entity's intangible assets. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark. Licensing fees are generally, but not always, fixed as to amount and not dependent upon the revenue generated by the licensing party. An entity may receive licensing fees for licenses that also generate royalty payments to the entity.

+ 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(e))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

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License and Collaboration Agreements (Details Textual) (USD $) In Millions, unless otherwise specified		1 Months Ended	3 Months Ended			3 Months Ended	12 Months Ended				3 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2009 Hoffmann-La Roche [Member] License Option [Member]	Dec. 31, 2010 Amgen Inc [Member]	Mar. 31, 2012 Amgen Inc [Member]	Mar. 31, 2012 AstraZeneca AB [Member]	Mar. 31, 2012 Bayer Healthcare LLC [Member]	Dec. 31, 2007 Bayer Healthcare LLC [Member] Up-front Payment Arrangement [Member]	Dec. 31, 2007 Bayer Healthcare LLC [Member] Performance milestone payments [Member]	Dec. 31, 2005 Baxter Healthcare [Member]	Mar. 31, 2012 Baxter Healthcare [Member]	Dec. 31, 2009 NKTR-118 and NKTR-119 [Member] AstraZeneca AB [Member] Up-front Payment Arrangement [Member]	Mar. 31, 2012 MIRCERA [Member] Hoffmann-La Roche [Member]	Feb. 29, 2012 MIRCERA [Member] Hoffmann-La Roche [Member] Up-front Payment Arrangement [Member]	Mar. 31, 2012 MIRCERA [Member] Hoffmann-La Roche [Member] Up-front Payment Arrangement [Member]	Mar. 31, 2012 MIRCERA [Member] Hoffmann-La Roche [Member] Performance milestone payments [Member]	Feb. 29, 2012 MIRCERA [Member] Hoffmann-La Roche [Member] Performance milestone payments [Member]	Mar. 31, 2012 NKTR-118 [Member]	Mar. 31, 2012 NKTR-118 [Member] AstraZeneca AB [Member]	Mar. 31, 2012 NKTR-119 [Member] AstraZeneca AB [Member]	Mar. 31, 2012 Hemophilia [Member] Baxter Healthcare [Member]	Mar. 31, 2012 Hemophilia B [Member] Baxter Healthcare [Member]	Mar. 31, 2012 OMONTYS [Member] Affymax Inc [Member]	Mar. 27, 2012 OMONTYS [Member] Affymax Inc [Member]	Mar. 31, 2012 PEGASYS [Member] Hoffmann-La Roche [Member]
License and Collaboration Agreements (Textual) [Abstract]
Potential future payments for development milestones	$ 172.1					$ 60.0										$ 22.0				$ 28.0	$ 11.0
Substantive milestone revenue																							2.0
Deferred Revenue				42.9		26.7				5.5		7.9										7.7		19.2
Received upfront and milestone payments		31.0	50.0				40.0	20.0	9.0		125.0		5.0	5.0	3.0
Revenue recognized as contractual obligations completed												0.1
Contingent payments receivable based on development events to be pursued and completed solely by others					95.0												140.0	235.0	75.0
Performance milestone to be used to reimburse future clinical trial costs						10.0
Expected sales consideration												$ 27.0