Amount of amortization expense attributable to the sale of future royalties.

No definition available.

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- Definition

Amount of interest expense using the effective interest rate method related to the sale of future royalties.

+ References

No definition available.

+ Details

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- Definition

Amount, before accumulated amortization, of the liability related to the sale of future royalties, pursuant to a royalty purchase agreement, that the Company is entitled to receive under collaboration agreements with Biogen and Novartis. The balance will be amortized over the estimated life of the arrangement using the effective interest rate method.

+ References

No definition available.

+ Details

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

- Definition

Amount, after accumulated amortization, of the unamortized liability related to the sale of future royalties, pursuant to a royalty purchase agreement, that the Company is entitled to receive under collaboration agreements with Biogen and Novartis. The balance will be amortized over the estimated life of the arrangement using the effective interest rate method.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum amount of annual sales on which royalty payments are paid under the royalty purchase agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum amount of payments receivable for additional milestones under the royalty purchase agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Maximum royalty payments under the royalty purchase agreement made before royalty interest reverts back to the Company.

+ References

No definition available.

+ Details

Name:	ions_MaximumRoyaltyPaymentsMadeBeforeRoyaltyInterestRevertsBack
Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow paid to third parties for transaction costs in connection with a monetization transaction of future SPINRAZA and pelacarsen royalties the Company is entitled to under collaboration and licensing agreements.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percentage of royalty payments paid on annual sales of medicine.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from the sale of future royalties under a royalty purchase agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of royalty payments made during the period under a royalty purchase agreement.

+ References

No definition available.

+ Details

Name:	ions_RoyaltyPayments
Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482900/835-30-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482925/835-30-45-2

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-6

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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- Details

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Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2023	Sep. 30, 2023	Sep. 30, 2022
Royalty Revenue Monetization [Abstract]
Transaction costs		$ 10,434	$ 0
Proceeds from sale of future royalties		500,000	0
Royalty payments to Royalty Pharma		(27,814)	0
Interest expense related to sale of future royalties		50,541	0
Issuance costs related to sale of future royalties		(10,434)	$ 0
Net liability related to sale of future royalties		512,700
Royalty Purchase Agreement [Member]
Royalty Revenue Monetization [Abstract]
Upfront payment received	$ 500,000
Maximum amount of payments receivable for additional milestones		625,000
Transaction costs		$ 10,434
Effective interest rate		13.50%
Proceeds from sale of future royalties		$ 500,000
Royalty payments to Royalty Pharma		(27,814)
Interest expense related to sale of future royalties		50,541
Liability related to sale of future royalties		522,727
Issuance costs related to sale of future royalties		(10,434)
Amortization of issuance costs related to sale of future royalties		407
Net liability related to sale of future royalties		512,700
Royalty Purchase Agreement [Member] \| SPINRAZA [Member]
Royalty Revenue Monetization [Abstract]
Maximum amount of annual sales on which royalty payments are paid		$ 1,500,000
Royalty Purchase Agreement [Member] \| SPINRAZA [Member] \| Minimum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine		25.00%
Maximum royalty payments made before royalty interest reverts back		$ 475,000
Royalty Purchase Agreement [Member] \| SPINRAZA [Member] \| Maximum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine		45.00%
Maximum royalty payments made before royalty interest reverts back		$ 550,000
Royalty Purchase Agreement [Member] \| Pelacarsen [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine		25.00%