The period over which shares can be exercised from grant date.

No definition available.

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- Definition

The percentage of share options forfeited.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period which the right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

The number of other equity instruments (i.e other than share options) exercised in a share-based payment arrangement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of share options issued in a share-based payment arrangement.

+ References

No definition available.

+ Details

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Namespace Prefix:	afmd_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of tranches under share based award.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of fair value of shares at grant date.

+ References

No definition available.

+ Details

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Namespace Prefix:	afmd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The preceding consecutive trading period should be considered for weighted average share price.

+ References

No definition available.

+ Details

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Namespace Prefix:	afmd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The option life of share options granted.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_47_a_i&doctype=Standard
-URIDate 2019-03-27

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The exercise price of outstanding share options.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45_d&doctype=Standard
-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of expense from share-based payment transactions with employees.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of other equity instruments (ie other than share options) granted in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
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-IssueDate 2019-01-01
-Paragraph 45
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45&doctype=Standard
-URIDate 2019-03-27

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of other equity instruments (ie other than share options) exercised or vested in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45&doctype=Standard
-URIDate 2019-03-27

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of other equity instruments (ie other than share options) forfeited in a share-based payment arrangement.

+ References

+ Details

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of other equity instruments (ie other than share options) outstanding in a share-based payment arrangement.

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of share options exercisable in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
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-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of share options granted in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-Subparagraph b
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45_b_ii&doctype=Standard
-URIDate 2019-03-27

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of other equity instruments (ie other than share options) exercised or vested in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average remaining contractual life of outstanding share options. [Refer: Weighted average [member]]

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average share price. [Refer: Weighted average [member]]

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-Subparagraph c
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-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

Name:	afmd_IfrsVestingAxis=afmd_TrancheIiiMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	afmd_NatureOfExpensesAxis=afmd_ResearchAndDevelopmentMember
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- Details

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17. Share Based Payments - Narrative (Details) $ in Thousands			12 Months Ended
	Apr. 20, 2018 USD ($) Y tranche $ / shares shares	Apr. 20, 2018 EUR (€) Y tranche shares	Dec. 31, 2019 EquityInstruments USD ($) $ / shares	Dec. 31, 2019 EUR (€) EquityInstruments Y shares	Dec. 31, 2018 EquityInstruments $ / shares	Dec. 31, 2018 EUR (€) EquityInstruments Y shares	Dec. 31, 2017 EUR (€)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period (in years)	3 years	3 years
Number of options issued \| €		240,000
Number of tranches \| tranche	3	3
Trading days	15 days	15 days
Share price at grant date			$ 1.44		$ 1.91
Grant date fair value	$ 164	€ 133,000
Expected life \| Y	2	2		5.9		5.9
Options exercisable \| $			0
Share-based expense \| €				€ 2,469,000		€ 2,035,000	€ 1,943,000
Number of options issued \| shares	240,000	240,000
Tranche I
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share price at grant date	$ 6.15
Tranche II
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share price at grant date	8.20
Tranche III
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share price at grant date	$ 10.25
Research and Development
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based expense \| €				904,000		852,000	522,000
General and Administrative
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based expense \| €				€ 1,565,000		€ 1,183,000	€ 1,421,000
ESOP 2014
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period (in years)				3 years
Awards granted \| EquityInstruments				1,736,803		2,332,296
Awards cancelled or forfeited \| EquityInstruments				357,879		424,688
Awards outstanding \| EquityInstruments			7,307,567		5,948,438
Awards exercised \| shares				19,795		40,038
Average exercise price of awards exercised			$ 1.54		$ 1.98
Awards vested \| EquityInstruments				4,773,840		2,814,547
Annual forfeiture rate				4.00%		4.00%
Weighted average remaining contractual life				8 years 10 months 24 days		9 years 3 months 18 days
Exercise period				10 years
ESOP 2014 \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price			1.30		1.30
ESOP 2014 \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price			$ 13.47		$ 13.47