Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 16, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	DELCATH SYSTEMS, INC.
Entity Central Index Key	0000872912
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 82,287,147
Entity Common Stock, Shares Outstanding		434,997,075
Document Fiscal Year Focus	2017
Trading Symbol	DCTH
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017