Net (Loss) Income per Share - Narrative (Details) - shares	Mar. 31, 2026	Mar. 31, 2025
Earnings Per Share [Abstract]
Pre-funded warrants outstanding (in shares)	1,341,375	1,341,375

Number of shares pre-funded penny warrants outstanding.

No definition available.

Name:	dcth_NumberOfSharesPreFundedPennyWarrantsOutstanding
Namespace Prefix:	dcth_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant