Financial Instruments and Risk Management - Contractual undiscounted outflows (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Carrying amount	$ 2,846	$ 859
Contractual cash flow	2,846	878
Less than one year
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Contractual cash flow	2,846	878
Lease liabilities
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Carrying amount	20	36
Contractual cash flow	20	55
Lease liabilities \| Less than one year
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Contractual cash flow	20	55
Trade payables
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Carrying amount	2,646	646
Contractual cash flow	2,646	646
Trade payables \| Less than one year
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Contractual cash flow	2,646	646
Other payables
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Carrying amount	180	177
Contractual cash flow	180	177
Other payables \| Less than one year
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Contractual cash flow	$ 180	$ 177

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of financial liabilities at amortised cost. The amortised cost is the amount at which financial liabilities are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount. [Refer: Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 8
-Subparagraph g
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_8_g&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 8
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_8_f&doctype=Standard&book=b
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_FinancialLiabilitiesAtAmortisedCost
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of contractual undiscounted cash flows in relation to non-derivative financial liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 39
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_39_a&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NonderivativeFinancialLiabilitiesUndiscountedCashFlows
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfLiabilitiesAxis=ifrs-full_LeaseLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfLiabilitiesAxis=evax_TradePayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfLiabilitiesAxis=evax_OtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: