Commitments - Schedule Future Minimum Lease Payments, Net of Receipts Due Under Terms of Subleases Under All Operating Leases (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Future minimum lease payments under all operating leases [Abstract]
2021	$ 419
2022	406
2023	$ 68

Operating lease liability future minimum sublease rentals due next twelve months.

No definition available.

Name:	dcth_OperatingLeaseLiabilityFutureMinimumSubleaseRentalsDueNextTwelveMonths
Namespace Prefix:	dcth_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant