v3.26.1

Equity - Incentive Equity Awards - Additional Information (Detail) - shares	1 Months Ended
	Jan. 31, 2026	Jan. 31, 2025
Employees \| Stock Incentive Plan 2020 \| Restricted Stock Units (RSUs)
Stockholders Equity Note [Line Items]
Stock units, Granted	5,615,880
Stock options, Vest		50.00%
Stock units, Vesting Period	3 years
Employees \| Stock Incentive Plan 2020 \| Stock Options
Stockholders Equity Note [Line Items]
Stock options, Granted	5,570,420
Stock options, Vest		50.00%
Stock units, Vesting Period	3 years
Stock units, Cliff Vesting Period	1 year
Board of Directors \| Restricted Stock Units (RSUs)
Stockholders Equity Note [Line Items]
Stock units, Granted		10,646,844
Board of Directors \| Stock Options
Stockholders Equity Note [Line Items]
Stock options, Granted		3,313,059

Share-based compensation arrangement by share-based payment award, award cliff vesting period.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Options Vest Percentage

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- Definition

Stockholders Equity Note [Line Items]

+ References

No definition available.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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- Definition

Net number of share options (or share units) granted during the period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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AMARIN CORP PLC\UK 10-Q