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Cumulative amount of milestone payments, license fees and/or upfront fees received under the collaborative arrangement as of the end of the reporting period.

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Represents the maximum amount of payments receivable under the agreement.

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No definition available.

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Represents the minimum amount of payments receivable under the agreement.

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No definition available.

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Represents the next potential milestone payment to be earned.

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No definition available.

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Represents the number of drugs currently in clinical development under the collaboration agreement.

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Represents the amount of upfront fees received during the period under the agreement.

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No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

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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).

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Collaborative Arrangements and Licensing Agreements, Research, Development and Commercialization Partners - GSK (Details) $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Jan. 31, 2016 USD ($)	Mar. 31, 2010 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Drug	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned			$ 51,571	$ 49,121	$ 120,428	$ 62,583	$ 84,861	$ 44,063	$ 57,076	$ 28,161	$ 283,703	$ 214,161	$ 147,285
GSK [Member] \| Collaborations and Licensing Agreements [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs currently in development \| Drug											5
Upfront fee received		$ 38,000
Cumulative payments and/or fees received			135,000								$ 135,000
Next potential milestone			5,000								5,000
Revenue earned											33,300	37,300	$ 35,300
Deferred revenue			4,900				$ 10,000				$ 4,900	$ 10,000
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Subsequent Event [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Milestone payment earned	$ 1,500
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage											12.00%	17.00%	24.00%
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Pre Specified Events [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Minimum amount of payments receivable			1,000,000								$ 1,000,000
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Pre-Licensing Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			10,000								10,000
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Development Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			183,500								183,500
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Regulatory Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			363,500								363,500
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| Commercialization Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			348,000								348,000
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| IONIS-TTR [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments and/or fees received			$ 60,000								$ 60,000
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| IONIS-HBV, IONIS-HBV-L, IONIS-GSK4-L, and IONIS-RHO-2.5 [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs currently in development \| Drug											4
GSK [Member] \| Collaborations and Licensing Agreements [Member] \| IONIS-HBV and IONIS-HBV-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs currently in development \| Drug											2