| Document and Entity Information | Mar. 25, 2022 |
| Cover [Abstract] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0000872912 |
| Document Type | 8-K |
| Document Period End Date | Mar. 25, 2022 |
| 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 | 1633 Broadway |
| Entity Address, Address Line Two | Suite 22C |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10019 |
| 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, $.01 par value |
| Trading Symbol | DCTH |
| Entity Emerging Growth Company | false |
