Closing bid price.

No definition available.

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

- Definition

Convertible preferred stock conversion price per share.

+ References

No definition available.

+ Details

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

- Definition

Deemed dividend amount.

+ References

No definition available.

+ Details

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

- Definition

Number of investors.

+ References

No definition available.

+ Details

Name:	dcth_NumberOfInvestors
Namespace Prefix:	dcth_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of votes.

+ References

No definition available.

+ Details

Name:	dcth_NumberOfVotes
Namespace Prefix:	dcth_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds from issuance of private placement gross.

+ References

No definition available.

+ Details

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

- Definition

Stockholders equity note.

+ References

No definition available.

+ Details

Name:	dcth_StockholdersEquityNoteLineItems
Namespace Prefix:	dcth_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued for each share of convertible preferred stock that is converted.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

+ Details

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

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

+ Details

Name:	us-gaap_DebtConversionOriginalDebtAmount1
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 redemption (or callable) amount of currently redeemable preferred stock. Includes amounts representing dividends not currently declared or paid but which will be payable under the redemption features or for which ultimate payment is solely within the control of the issuer.

+ References

+ Details

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

- Definition

The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21564-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21488-112644

+ Details

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

- Definition

Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

+ References

No definition available.

+ Details

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

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-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_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=dcth_SeniorSecuredConvertibleNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

Stockholders' Equity - Preferred Stock Issuances - Additional Information (Details)														1 Months Ended			6 Months Ended	12 Months Ended
	Sep. 21, 2017 USD ($) Investor Vote $ / shares shares	Aug. 28, 2017 USD ($) shares	Aug. 04, 2017 USD ($)	Jul. 11, 2017 USD ($) Vote $ / shares	Jul. 07, 2017 USD ($)	Jul. 02, 2017 USD ($) Vote $ / shares shares	May 09, 2017 USD ($)	Apr. 10, 2017 USD ($)	Mar. 13, 2017 USD ($)	Mar. 02, 2017 USD ($)	Feb. 10, 2017 USD ($)	Feb. 01, 2017 USD ($)	Jan. 12, 2017 USD ($)	Oct. 31, 2016 USD ($)	Feb. 28, 2015 USD ($)	Oct. 31, 2013 USD ($)	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 28, 2017 USD ($)	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Nov. 06, 2017 USD ($)	Sep. 12, 2017 $ / shares	Jun. 29, 2017 $ / shares
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) \| $ / shares																	$ 0.01	$ 0.01		$ 0.01
Conversion of convertible notes			$ 1,015,848		$ 2,000,000		$ 1,913,915	$ 3,621,286	$ 4,417,829	$ 125,999	$ 3,045,817	$ 544,000	$ 1,478,318					$ 40,121,000	$ 35,000,000	$ 649,000	$ 0
Sale of stock in private placement																				1,011,000	8,479,000
Gross proceeds from the sale of shares														$ 1,200,000	$ 2,600,000	$ 7,500,000
Deemed dividend amount																		$ 527,000		$ 0	$ 0
Restructuring Agreement [Member]
Stockholders Equity Note [Line Items]
Conversion of convertible notes		$ 1,200,000
Series A Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) \| $ / shares																								$ 0.01
Number of Shares \| shares						4,200
Closing bid price \| $ / shares						$ 1,288.00
Number of votes \| Vote						3,261
Preferred stock redemption price per share \| $ / shares						$ 0.001
Series A Preferred Stock [Member] \| Senior Secured Convertible Notes [Member]
Stockholders Equity Note [Line Items]
Conversion of convertible notes						$ 4,200,000
Series B Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) \| $ / shares																								$ 0.01
Closing bid price \| $ / shares				$ 65.35
Number of votes \| Vote				30,607
Sale of stock in private placement				$ 2,360,000
Cash purchase price in private placement				2,000,000
Gross proceeds from the sale of shares				$ 2,000,000
Conversion price per share \| $ / shares				$ 53.55
Deemed dividend amount																	$ 360,000
Series B Preferred Stock [Member] \| Restructuring Agreement [Member]
Stockholders Equity Note [Line Items]
Redeemed share \| shares		2,360,000
Series C Preferred Shares [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) \| $ / shares																							$ 0.01
Conversion of convertible notes	$ 500,000
Number of Shares \| shares	590
Number of votes \| Vote	1,484,061
Preferred stock redemption price per share \| $ / shares	$ 1,000.00
Number of investors \| Investor	2
Redemption of preferred stock																						$ 590,000