| Document and Entity Information | Dec. 23, 2024 |
| Cover [Abstract] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0000872912 |
| Document Type | 8-K |
| Document Period End Date | Dec. 23, 2024 |
| Entity Registrant Name | Delcath Systems, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-16133 |
| Entity Tax Identification Number | 06-1245881 |
| Entity Address, Address Line One | 566 Queensbury Avenue |
| Entity Address, City or Town | Queensbury |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 12804 |
| City Area Code | (212) |
| Local Phone Number | 489-2100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value per share |
| Trading Symbol | DCTH |
| Entity Emerging Growth Company | false |
