v3.25.2
Cover Page - shares
6 Months Ended
Jun. 30, 2025
Jul. 31, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-16133  
Entity Registrant Name DELCATH SYSTEMS, INC.  
Entity Incorporation, State or Country Code DE  
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 518  
Local Phone Number 743-8892  
Title of 12(b) Security Common stock, $0.01 par value per share  
Trading Symbol DCTH  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   34,981,253
Entity Central Index Key 0000872912  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false