Description of Business	12 Months Ended
Description of Business	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business The Company is an interventional oncology company focused on the treatment of primary and cancers metastatic to the liver. The Company’s lead product, the HEPZATOTM KIT (“HEPZATO” melphalan for Injection/Hepatic Delivery System), a drug/device combination product, was approved by the US Food and Drug Administration (the “FDA”) on August 14, 2023, indicated as a liver-directed treatment for adult patients with uveal melanoma with unresectable hepatic metastases affecting less than 50% of the liver and no extrahepatic disease, or extrahepatic disease limited to the bone, lymph nodes, subcutaneous tissues, or lung that is amenable to resection, or radiation. In Europe, the hepatic delivery system is a stand-alone medical device having the same device components as HEPZATO KIT, but without the melphalan hydrochloride and is approved for sale under the trade name CHEMOSAT Hepatic Delivery System for Melphalan, or CHEMOSAT, where it has been used at major medical centers to treat a wide range of cancers in the liver. The first commercial use of HEPZATO for the treatment of mUM occurred in January 2024. In the United States, HEPZATO is considered a combination drug and device product and is regulated as a drug by the FDA. Primary jurisdiction for regulation of HEPZATO has been assigned to the FDA’s Center for Drug Evaluation and Research. The FDA has granted Delcath six orphan drug designations (five for melphalan in the treatment of patients with ocular (uveal) melanoma, cutaneous melanoma, intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and neuroendocrine tumor indications and one for doxorubicin in the treatment of patients with hepatocellular carcinoma). The Company has sufficient raw material and component constituent parts of HEPZATO KIT to meet the first year of its anticipated demand and it intends to manage supply chain risk through stockpiled inventory and contracting with multiple suppliers for critical components. On February 28, 2022, CHEMOSAT received Medical Device Regulation (MDR) certification under the European Medical Devices Regulation (EU) 2017/745, which may be considered by jurisdictions when evaluating reimbursement. As of March 1, 2022, the Company assumed direct responsibility for sales, marketing and distribution of CHEMOSAT in Europe. The Company’s clinical development program for HEPZATO was comprised of the FOCUS Clinical Trial for Patients with metastatic hepatic dominant Uveal Melanoma (the “FOCUS Trial”), a global registration clinical trial that investigated objective response rate in patients with metastatic uveal melanoma (“mUM”). The current focus of the Company’s clinical development program is to generate clinical data for CHEMOSAT and HEPZATO in patients with mUM, either as monotherapy or in combination with immunotherapy. The Company extects that this will support increased clinical adoption of and reimbursement for CHEMOSAT in Europe, and to support reimbursement in various jurisdictions, including the United States. In addition to HEPZATO’s use to treat mUM, the Company believes that HEPZATO has the potential to treat cancers in the liver, such as metastatic colorectal cancer, metastatic neuroendocrine tumors, metastatic breast cancer and intrahepatic cholangiocarcinoma, and plans to begin one or more studies of HEPZATO KIT to treat such conditions in 2024. The Company believes that those and similar disease states are areas of unmet medical needs that represent significant market opportunities. Risks and Uncertainties The Company is subject to risks common to companies in the biopharmaceutical industry including, but not limited to, the risks associated with developing product candidates and successfully launching and commercializing its drug/device combination products, the Company’s ability to obtain regulatory approval of its such products in the United States and other geography markets, the uncertainty of the broad adoption of its approved products by physicians and consumers, and significant competition. In addition, high rates of inflation have resulted in the U.S. Federal Reserve raising interest rates. Increases in interest rates, especially if coupled with reduced government spending and volatility in financial markets, may further increase economic uncertainty and heighten these risks. Furthermore, if additional banks and financial institutions enter receivership or become insolvent in the future in response to financial conditions affecting the banking system and financial markets, the Company or its partners’ ability to access existing cash, cash equivalents and investments may be threatened and could have a material adverse effect on the Company’s business and financial condition, including the Company’s ability to access additional capital on favorable terms, or at all, which could in the future negatively affect the Company’s ability to pursue its business strategy. Liquidity and Going Concern On December 31, 2023, the Company had cash, cash equivalents and restricted cash totaling $12.7 million and short-term investments totaling $19.8 million, as compared to cash, cash equivalents and restricted cash totaling $11.8 million at December 31, 2022. During the twelve months ended December 31, 2023, the Company used $31.3 million of cash in its operating activities and $6.3 million for principal payments. The Company’s future results are subject to substantial risks and uncertainties. The Company has operated at a loss for its entire history and there can be no assurance that it will ever achieve or maintain profitability. The Company has historically funded its operations primarily with proceeds from sales of common stock, warrants and prefunded warrants for the purchase of common stock, sales of preferred stock, proceeds from the issuance of convertible debt and borrowings under loan and security agreements. If there is a substantial delay in the activation of sites approved to administer HEPZATO, the Company expects to need to raise additional capital under structures available to the Company, including debt and/or equity offerings, which may not be on favorable terms. In a substantially delayed site activation scenario, the Company would not have sufficient funds to meet its obligations within twelve months from the issuance date of these condensed consolidated financial statements. As such, there is uncertainty regarding the Company’s ability to maintain liquidity sufficient to operate its business effectively, which raises substantial doubt about the Company’s ability to continue as a going concern. Debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If the Company raises funds through collaborations, or other similar arrangements with third parties, it may have to relinquish valuable rights to its technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to the Company and/or may reduce the value of its common stock. If the Company is unable to raise additional funds through equity or debt financings when needed, it may be required to delay, limit, reduce or terminate its product development or future commercialization efforts or grant rights to develop and market its product candidates even if the Company would otherwise prefer to develop and market such product candidates itself. The Company also expects to use cash and cash equivalents to fund activities relating to commercial support for HEPZATO, CHEMOSAT and any future clinical research trials and operating activities. The Company’s future liquidity and capital requirements will depend on numerous factors, including the initiation and progress of clinical trials and research and product development programs; obtaining regulatory approvals and complying with applicable laws and regulations; the timing and effectiveness of product commercialization activities, including marketing arrangements; the timing and costs involved in preparing, filing, prosecuting, defending and enforcing intellectual property rights; and the effect of competing technological and market developments. The Company’s capital commitments over the next twelve months include (a) $6.3 million to satisfy accounts payable, accrued expenses, current lease liabilities and current medac settlement and (b) $10.6 million of loan and convertible note principal payments, if the holders do not elect to convert up to $5.0 million of the notes into equity. Additional capital commitments beyond the next twelve months include (a) less than $0.1 million of lease liabilities; and (b) $0.8 million for settlement of litigation with medac.