| Cover | Oct. 15, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 15, 2021 |
| Entity File Number | 001-37977 |
| Entity Registrant Name | AVADEL PHARMACEUTICALS PLC |
| Entity Central Index Key | 0001012477 |
| Entity Tax Identification Number | 98-1341933 |
| Entity Incorporation, State or Country Code | L2 |
| Entity Address, Address Line One | 10 Earlsfort Terrace |
| Entity Address, City or Town | Dublin 2 |
| Entity Address, Country | IE |
| Entity Address, Postal Zip Code | D02 T380 |
| City Area Code | 353 |
| Local Phone Number | 1 920 1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | American Depositary Shares* |
| Trading Symbol | AVDL |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
