Number of renewal options.

No definition available.

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- Definition

Operating lease change in weighted average discount rate percent.

+ References

No definition available.

+ Details

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- Definition

Operating lease commencement date.

+ References

No definition available.

+ Details

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- Definition

Short term lease period.

+ References

No definition available.

+ Details

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- Definition

Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Description of lessee's operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

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- Definition

Indicates (true false) whether lessee has option to extend operating lease.

+ References

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- Definition

Indicates (true false) whether lessee has option to terminate operating lease.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in next fiscal year following latest fiscal year.

+ References

+ Details

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- Definition

Description of terms and conditions of option to extend lessee's operating lease. Includes, but is not limited to, information about option recognized as part of right-of-use asset and lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-SubTopic 20
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-Paragraph 3
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- Definition

Description of terms and conditions of option to terminate lessee's operating lease. Includes, but is not limited to, information about option recognized as part of right-of-use asset and lease liability.

+ References

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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

Amount of operating lease expense. Excludes sublease income.

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

+ References

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- Definition

Indicates line item in statement of financial position that includes current operating lease liability.

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- Definition

Amount of lessee's right to use underlying asset under operating lease.

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- Definition

Weighted average discount rate for operating lease calculated at point in time.

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Leases - Additional Information (Detail) $ in Thousands						3 Months Ended	6 Months Ended
Leases - Additional Information (Detail) $ in Thousands	Aug. 15, 2019 USD ($) RenewalOption	Jul. 04, 2019	Apr. 12, 2019	Jan. 26, 2019	Jul. 01, 2011	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lessee Lease Description [Line Items]
Incremental borrowing rate for purposes of calculation of lease liabilities						11.50%	11.50%
Change in incremental borrwing rate							1.00%
Short-term lease commited aggregate payment amount						$ 200	$ 200
Monthly rent payment						18,224	18,224
Operating lease liability						9,300	9,300
Current operating lease liability						$ 1,126	$ 1,126
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]						amrn:AccruedLiabilitiesAndOtherLiabilitiesCurrent	amrn:AccruedLiabilitiesAndOtherLiabilitiesCurrent
Operating lease right-of-use asset						$ 8,762	$ 8,762
Operating lease expense						$ 400	$ 700
Dublin \| Office Centre Sharing Agreements
Lessee Lease Description [Line Items]
Description of lease agreement							On April 12, 2019 and July 4, 2019, the Company entered into Office Centre Sharing Agreements effective May 1, 2019 and October 1, 2019, respectively, to replace the office space with new office space in Dublin, Ireland which terminate on April 30, 2020 and September 30, 2020, respectively, and can be extended automatically for successive one year periods.
Lease termination existence of option to extend							true
Lease renewal term						1 year	1 year
Operating lease, option to extend							can be extended automatically for successive one year periods.
Operating lease, existence of option to extend [true false]							true
Dublin \| Office Centre Sharing Agreements Effective May 1, 2019
Lessee Lease Description [Line Items]
Operating lease, expiration date			Apr. 30, 2020
Dublin \| Office Centre Sharing Agreements Effective October 1, 2019
Lessee Lease Description [Line Items]
Operating lease, expiration date		Sep. 30, 2020
Bedminster
Lessee Lease Description [Line Items]
Operating lease, expiration date				Sep. 15, 2019	Sep. 15, 2019
Bridgewater
Lessee Lease Description [Line Items]
Description of lease agreement							Amarin will have a one-time option to terminate the agreement effective on the first day of the ninety-seventh month after the Commencement Date upon advance written notice and a termination payment specified in the Lease.
Lease termination description							one-time option to terminate the agreement effective on the first day of the ninety-seventh month after the Commencement Date
Bridgewater \| Scenario Forecast
Lessee Lease Description [Line Items]
Lease termination existence of option to extend	true
Lease renewal term	5 years
Lease commencement date	Aug. 15, 2019
Lease agreement term	11 years
Number of renewal options \| RenewalOption	2
Monthly rent payment	$ 100
Maximum
Lessee Lease Description [Line Items]
Short term lease period							12 months