XML 35 R28.htm IDEA: XBRL DOCUMENT v3.24.1.u1

Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) Segment Customer	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Significant Accounting Policies [Line Items]
Trade receivables, credit period	45 days
Maturities period	24 months
Unrealized gain (loss) on held-to-maturity securities	$ 100	$ 200
Number of operating segments | Segment	1
Charges of recognized within Cost of goods sold restructuring inventory	$ 0	$ 12,254
Organizational Restructuring Plan
Significant Accounting Policies [Line Items]
Restructuring expenses			$ 11,000
Restructuring and transformation initiative expense			$ 11,000
Short Term Investments
Significant Accounting Policies [Line Items]
Maturities period	12 months
Long Term Investments
Significant Accounting Policies [Line Items]
Maturities period	12 months
Money Market Instruments
Significant Accounting Policies [Line Items]
Maturities period	90 days
Gross Product Sales | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Number of customers | Customer	3
Customer A | Gross Product Sales | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	28.00%	29.00%
Customer A | Accounts Receivable | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	37.00%	36.00%
Customer B | Gross Product Sales | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	35.00%	38.00%
Customer B | Accounts Receivable | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	31.00%	40.00%
Customer C | Gross Product Sales | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	29.00%	27.00%
Customer C | Accounts Receivable | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage	22.00%	20.00%
Earliest Tax Year | Internal Revenue Service (IRS)
Significant Accounting Policies [Line Items]
Open tax year	2018
Earliest Tax Year | New Jersey Department of Treasury
Significant Accounting Policies [Line Items]
Open tax year	2012
Latest Tax Year | Internal Revenue Service (IRS)
Significant Accounting Policies [Line Items]
Open tax year	2019
Latest Tax Year | New Jersey Department of Treasury
Significant Accounting Policies [Line Items]
Open tax year	2015

X

- Definition

Accounts receivable credit period

+ References

No definition available.

+ Details

Name:	amrn_AccountsReceivableCreditPeriod
Namespace Prefix:	amrn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Cost of goods and services sold restructuring inventory.

+ References

No definition available.

+ Details

Name:	amrn_CostOfGoodsAndServicesSoldRestructuringInventory
Namespace Prefix:	amrn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Held to maturity securities continuous unrealized gain (loss) position fair value.

+ References

No definition available.

+ Details

Name:	amrn_HeldToMaturitySecuritiesContinuousUnrealizedGainLossPositionFairValue
Namespace Prefix:	amrn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of customers.

+ References

No definition available.

+ Details

Name:	amrn_NumberOfCustomers
Namespace Prefix:	amrn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Significant accounting policies.

+ References

No definition available.

+ Details

Name:	amrn_SignificantAccountingPoliciesLineItems
Namespace Prefix:	amrn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-21

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-20

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482861/275-10-50-18

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482861/275-10-50-20

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-18

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tax year that remains open to examination under enacted tax laws, in YYYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_OpenTaxYear
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:gYearListItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479823/420-10-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 420
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482047/420-10-45-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479823/420-10-S99-1

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_RestructuringPlanAxis=amrn_OrganizationalRestructuringPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=amrn_LongTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=amrn_MoneyMarketInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=amrn_CustomerAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=amrn_CustomerBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=amrn_CustomerCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_EarliestTaxYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_NewJerseyDivisionOfTaxationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_LatestTaxYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: