Class of warrant or right, number of warrants available for cancellation.

No definition available.

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

- Definition

Common stock subscription price per share.

+ References

No definition available.

+ Details

Name:	dcth_CommonStockSubscriptionPricePerShare
Namespace Prefix:	dcth_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument maturity period.

+ References

No definition available.

+ Details

Name:	dcth_DebtInstrumentMaturityPeriod
Namespace Prefix:	dcth_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Exchange of preferred stock stated value.

+ References

No definition available.

+ Details

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

- Definition

Issuance of senior secured promissory note in exchange of preferred stock.

+ References

No definition available.

+ Details

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

- Definition

Proceeds from exchange of preferred stock.

+ References

No definition available.

+ Details

Name:	dcth_ProceedsFromExchangeOfPreferredStock
Namespace Prefix:	dcth_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Warrant exercisible term.

+ References

No definition available.

+ Details

Name:	dcth_WarrantExercisibleTerm
Namespace Prefix:	dcth_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Monetary value of common stock allocated to investors to buy shares of a new issue of common stock before they are offered to the public. When stock is sold on a subscription basis, the issuer does not initially receive the total proceeds. In general, the issuer does not issue the shares to the investor until it receives the entire proceeds.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65888546&loc=d3e21300-112643

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesSubscriptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

+ Details

Name:	us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from issuance of callable preferred stock which is identified as being convertible to another type of financial security at the option of the issuer or the holder.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfRedeemableConvertiblePreferredStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

+ Details

Name:	us-gaap_SharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=dcth_RothCapitalPartnersLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=dcth_SeriesEConvertiblePreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TransactionTypeAxis=dcth_SecuritiesPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesDPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=dcth_SeriesDWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=dcth_PreFundedSeriesDWarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=dcth_TwoThousandAndNineteenWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events - Additional Information (Details) - USD ($)				1 Months Ended
	Jul. 11, 2019	Mar. 29, 2019	Mar. 29, 2019	May 23, 2019	Jun. 30, 2019	Jun. 06, 2019	Jan. 31, 2019	Dec. 31, 2018	Nov. 06, 2018	Nov. 05, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Debt instrument, principal face amount					$ 10,500,000	$ 2,000,000		$ 4,500,000
Interest rate on promissory note						8.00%
Preferred stock, par value (in dollars per share)					$ 0.01			$ 0.01			$ 0.01
Exercise price of warrants					0.23			0.22			1,569	$ 910,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Debt instrument, principal face amount				$ 3,300,000		$ 2,000,000
Interest rate on promissory note				8.00%		8.00%
Common stock subscription price per share							$ 1.75
Aggregate borrowed amount				$ 3,300,000
Maturity period				6 months
Roth Capital Partners, LLC [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Payments to private placement agent	$ 600,000
Series E Preferred Stock [Member] \| Private Placement [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Proceeds from private placement, gross	20,000,000
Series E Preferred Stock [Member] \| Private Placement [Member] \| Roth Capital Partners, LLC [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Payments to private placement agent	$ 1,400,000
Series E Preferred Stock [Member] \| Private Placement [Member] \| Securities Purchase Agreement [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Preferred stock, shares issued	20,000
Preferred stock, par value (in dollars per share)	$ 0.01
Shares issued, price per share	1,000
Series D Preferred Shares [Member]
Subsequent Event [Line Items]
Interest rate on promissory note		8.00%	8.00%
Preferred stock, par value (in dollars per share)										$ 0.01
Preferred stock, stated value		$ 1,160,000	$ 1,160,000
Issuance of senior secured promissory note in exchange of preferred stock		$ 1,560,000	$ 1,560,000
Maturity date		Apr. 01, 2020
Series D Preferred Shares [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Interest rate on promissory note		8.00%	8.00%
Preferred stock, stated value		$ 1,160,000	$ 1,160,000
Proceeds from exchanage of preferred stock			400,000
Issuance of senior secured promissory note in exchange of preferred stock		$ 1,560,000	$ 1,560,000
Maturity date			Apr. 01, 2020
Series D Preferred Shares [Member] \| Securities Purchase Agreement [Member]
Subsequent Event [Line Items]
Preferred stock, shares issued									101
Series D Warrants [Member]
Subsequent Event [Line Items]
Number of common shares issuable on cancellation of warrants						3,900,000
Series D Warrants [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Number of warrants available for cancellation						3,900,000
Pre-Funded Series D Warrants [Member]
Subsequent Event [Line Items]
Number of common shares issuable on cancellation of warrants						53,400,000
Pre-Funded Series D Warrants [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Number of common shares issuable on cancellation of warrants							7,900,000
Number of warrants available for cancellation						53,400,000
2019 Warrants [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Exercise price of warrants	$ 0.06
Warrant exercisable term	5 years
Maximum [Member]
Subsequent Event [Line Items]
Exercise price of warrants					10.00			10.00			19,712,000	19,712,000
Maximum [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock subscription price							$ 50,000,000
Minimum [Member]
Subsequent Event [Line Items]
Exercise price of warrants					$ 0.01			$ 0.01			$ 1,225	$ 281,750