Bridge loan, early termination interest rate.

No definition available.

Name:	dmrc_BridgeLoanEarlyTerminationInterestRate
Namespace Prefix:	dmrc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Bridge loan, fixed interest rate.

+ References

No definition available.

+ Details

Name:	dmrc_BridgeLoanFixedInterestRate
Namespace Prefix:	dmrc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Bridge loan, maximum amount.

+ References

No definition available.

+ Details

Name:	dmrc_BridgeLoanMaximumAmount
Namespace Prefix:	dmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Bridge loan, minimum draw amount.

+ References

No definition available.

+ Details

Name:	dmrc_BridgeLoanMinimumDrawAmount
Namespace Prefix:	dmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Closing costs.

+ References

No definition available.

+ Details

Name:	dmrc_ClosingCosts
Namespace Prefix:	dmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Shares Acquired.

+ References

No definition available.

+ Details

Name:	dmrc_NoncashAcquisitionSharesAcquiredValue
Namespace Prefix:	dmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of employees terminated prior to closing date.

+ References

No definition available.

+ Details

Name:	dmrc_PercentageOfEmployeesTerminatedPriorToClosingDate
Namespace Prefix:	dmrc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Product ARR Milestone.

+ References

No definition available.

+ Details

Name:	dmrc_ProductAnnualRecurringRevenueMilestone
Namespace Prefix:	dmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

+ Details

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

- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of liabilities assumed at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472

+ Details

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

- Definition

Face amount or stated value per share of common stock.

+ 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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
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

- Definition

Expiration date of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in YYYY-MM-DD format.

+ References

Reference 1: 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=123874694&loc=d3e19207-110258

+ Details

Name:	us-gaap_WarrantsAndRightsOutstandingMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=dmrc_EvrythngLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=dmrc_SecondPaymentStockPriceNotMoreThanFirstPaymentStockPriceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=dmrc_ProductARRMilestoneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=dmrc_ProductARRShortfallMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=dmrc_SecondPaymentStockPriceMoreThanFirstPaymentStockPriceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

Subsequent Event - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 15, 2021	Sep. 30, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Common stock, par value		$ 0.001	$ 0.001
Subsequent Event [Member] \| Evrythng Limited [Member]
Subsequent Event [Line Items]
Warrants and rights outstanding, maturity date	Mar. 27, 2022
Subsequent Event [Member] \| Evrythng Limited [Member] \| Second Payment Stock Price Not More Than First Payment Stock Price [Member] \| Product ARR Milestone [Member]
Subsequent Event [Line Items]
Business acquisition, common stock, value	$ 50,000
Subsequent Event [Member] \| Evrythng Limited [Member] \| Second Payment Stock Price Not More Than First Payment Stock Price [Member] \| Product ARR Shortfall [Member]
Subsequent Event [Line Items]
Business acquisition, common stock, value	50,000
Subsequent Event [Member] \| Evrythng Limited [Member] \| Second Payment Stock Price More Than First Payment Stock Price [Member] \| Product ARR Milestone [Member]
Subsequent Event [Line Items]
Business acquisition, common stock, value	100,000
Subsequent Event [Member] \| Evrythng Limited [Member] \| Second Payment Stock Price More Than First Payment Stock Price [Member] \| Product ARR Shortfall [Member]
Subsequent Event [Line Items]
Business acquisition, common stock, value	100,000
Subsequent Event [Member] \| Share Purchase Agreement [Member] \| Evrythng Limited [Member]
Subsequent Event [Line Items]
Noncash acquisition, shares acquired, value	$ 50,000
Common stock, par value	$ 0.001
Business acquisition, share price	$ 47.4823
Business combination, liabilities assumed	$ 7,900
Product annual recurring revenue milestone	$ 10,000
Percentage of employees terminated prior to closing date	20.00%
Closing costs	$ 8,000
Subsequent Event [Member] \| Bridge Loan Agreement [Member] \| Evrythng Limited [Member]
Subsequent Event [Line Items]
Bridge loan, maximum amount	2,000
Bridge loan, minimum draw amount	$ 250
Bridge loan, fixed interest rate	1.00%
Bridge loan, early termination interest rate	8.00%