v3.8.0.1
Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2017
Feb. 23, 2018
Jun. 30, 2017
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2017    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Trading Symbol AMRN    
Entity Registrant Name AMARIN CORP PLC\UK    
Entity Central Index Key 0000897448    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 1.1
American Depositary Shares      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   291,318,286  
Ordinary Shares      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   1,000,445