Selling, general and administrative expenses (Details) - EUR (€) € in Thousands	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Selling, general and administrative expenses
Personnel expenses	€ 36,549	€ 17,132
Consulting fees	18,998	6,795
Supervisory board	2,194	1,424
Other expense	3,903	2,111
Total	€ 61,644	€ 27,462

N/A

No definition available.

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- Definition

The expense of all forms of consideration given by an entity in exchange for a service rendered by employees or for the termination of employment classified as general and administrative expenses.

+ References

No definition available.

+ Details

Name:	argx_EmployeeBenefitExpensesClassifiedAsGeneralAndAdministrativeExpenses
Namespace Prefix:	argx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents expenses incurred in selling general and administrative not separately disclosed.

+ References

No definition available.

+ Details

Name:	argx_OtherSellingGeneralAndAdministrativeExpenses
Namespace Prefix:	argx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of fees paid or payable for supervisory board services.

+ References

No definition available.

+ Details

Name:	argx_SupervisoryBoardExpenses
Namespace Prefix:	argx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of expense relating to general and administrative activities of the entity.

+ 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

+ Details

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

- Definition

The amount of fees paid or payable for professional services.

+ References

+ Details

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