| Document and Entity Information | Nov. 05, 2019 |
| Cover [Abstract] | |
| Entity Registrant Name | AMARIN CORP PLC\UK |
| Amendment Flag | true |
| Amendment Description | Amarin Corporation plc (the “Company”) is filing this Amendment No. 1 to the Current Report on Form 8-K solely to correct a clerical error in the consolidated statement of operations data and the reconciliation of GAAP net income (loss) included in a press release issued on November 5, 2019 announcing its financial results for the three and nine months ended September 30, 2019 (the “Press Release”), which was furnished as Exhibit 99.1 to the Company’s Current Report on Form 8-K dated November 5, 2019 (the “Original Form 8-K”). While the Company’s Form 10-Q for the quarter ended September 30, 2019 and the Press Release accurately reflect the Company’s financial performance, due to a clerical error, the Original Form 8-K incorrectly presented certain financial data in the consolidated statement of operations data and the reconciliation of GAAP net income (loss) for the three and nine months ended September 30, 2019. Except as amended below, all other information in the Original Form 8-K remains unchanged. |
| Entity Central Index Key | 0000897448 |
| Document Type | 8-K/A |
| Document Period End Date | Nov. 5, 2019 |
| Entity Incorporation, State or Country Code | X0 |
| Entity File Number | 0-21392 |
| Entity Address, Address Line One | 77 Sir John Rogerson’s Quay |
| Entity Address, Address Line Two | Block C |
| Entity Address, Address Line Three | Grand Canal Docklands |
| Entity Address, City or Town | Dublin |
| Entity Address, Postal Zip Code | 2 |
| Entity Address, Country | IE |
| City Area Code | +353 1 |
| Local Phone Number | 6699 020 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | American Depositary Shares (ADS(s)), each ADS representing the right to receive one (1) Ordinary Share of Amarin Corporation plc |
| Trading Symbol | AMRN |
| Security Exchange Name | NASDAQ |
