XML 55 R37.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Organization and Significant Accounting Policies, Noncontrolling Interest in Akcea Therapeutics, Inc. (Details) - shares shares in Millions	3 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Jun. 30, 2017
Noncontrolling Interest in Akcea Therapeutics, Inc. [Abstract]
Additional shares of Akcea stock received for license of drug	6.9	2.8
Akcea [Member]
Noncontrolling Interest in Akcea Therapeutics, Inc. [Abstract]
Percentage ownership	76.00%		100.00%
Akcea [Member] | Minimum [Member]
Noncontrolling Interest in Akcea Therapeutics, Inc. [Abstract]
Percentage ownership	68.00%
Akcea [Member] | Maximum [Member]
Noncontrolling Interest in Akcea Therapeutics, Inc. [Abstract]
Percentage ownership	77.00%

X

- Definition

The number of additional shares of stock received from Akcea Therapeutics, Inc. as a sublicense fee in connection with Pfizer licensing AKCEA-ANGPTL3-L.

+ References

No definition available.

+ Details

Name:	ions_SharesReceivedFromSubsidiaryForLicenseOfDrug
Namespace Prefix:	ions_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromIssuanceOrSaleOfEquityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	srt_OwnershipAxis=ions_AkceaTherapeuticsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: