No definition available.

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- Definition

Cumulative amount of payments received under the collaboration agreement as of the end of the reporting period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

The maximum amount of payments receivable for commercialization milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The maximum amount of payments receivable for development milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The maximum amount of payments receivable for license fees and substantive milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The next potential milestone payment to be earned under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The amount of payments received during the period for advancing programs under the collaboration agreement.

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

The number of separate performance obligations under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The amount of consideration the Company is eligible to earn under the collaboration agreement, including any variable consideration.

+ References

No definition available.

+ Details

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- Definition

The royalty percentage received on gross margins of drug(s) under the collaborative arrangement.

+ References

No definition available.

+ Details

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- Definition

The amount of upfront payments received during the period under the collaboration agreement.

+ References

No definition available.

+ Details

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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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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Collaborative Arrangements and Licensing Agreements, Bayer (Details) $ in Thousands	1 Months Ended		3 Months Ended			6 Months Ended
	Feb. 28, 2017 USD ($) PerformanceObligation	May 31, 2015 USD ($) PerformanceObligation	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue			$ 117,747	$ 112,273		$ 262,165	$ 228,073
Deferred revenue								$ 233,362
Licensing and Other Royalties [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue			545	1,322		1,487	3,912
R&D [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue			60,549	$ 88,585		162,944	$ 196,584
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable for license fees and substantive milestones			385,000			385,000
Maximum amount of payments receivable for development milestones			125,000			125,000
Maximum amount of payments receivable for commercialization milestones			110,000			110,000
Cumulative payments received			175,000			175,000
Next prospective milestone			10,000			10,000
Number of separate performance obligations \| PerformanceObligation	3
Deferred revenue			$ 7,800			$ 7,800		$ 9,300
Bayer [Member] \| Revenue [Member] \| Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage			1.00%	0.00%		1.00%	29.00%
Bayer [Member] \| Minimum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Royalty percentage received on gross margins of both drugs combined						20.00%
Bayer [Member] \| R&D [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue			$ 800	$ 400		$ 1,500	$ 65,600
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment received		$ 100,000			$ 100,000
Number of separate performance obligations \| PerformanceObligation		3
Transaction price		$ 100,000
Bayer [Member] \| IONIS-FXI [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price		91,200
Revenue		91,200
Bayer [Member] \| R&D Services for IONIS-FXI [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price		4,300
Bayer [Member] \| IONIS-FXI API [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price		$ 4,500
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment received	$ 75,000
Payment received for advancing programs	$ 75,000
Number of separate performance obligations \| PerformanceObligation	2
Transaction price	$ 75,000
Bayer [Member] \| IONIS-FXI-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price	64,900
Bayer [Member] \| R&D Services for IONIS-FXI-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price	$ 10,100