Adjustments for decrease (increase) in monthly income plan personal income tax paid.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash compensation.

+ References

No definition available.

+ Details

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

- Definition

Marketing expenses.

+ References

No definition available.

+ Details

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

- Definition

Non-Employee director cash compensation per year.

+ References

No definition available.

+ Details

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

- Definition

Related party, lease liabilities.

+ References

No definition available.

+ Details

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Namespace Prefix:	birk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

TRA liability.

+ References

No definition available.

+ Details

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Namespace Prefix:	birk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amounts payable resulting from related party transactions. [Refer: Total for all related parties [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Number 24
-IssueDate 2024-01-01
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-URIDate 2024-03-27

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amounts receivable resulting from related party transactions. [Refer: Total for all related parties [member]]

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

The amount of compensation to key management personnel. [Refer: Key management personnel of entity or parent [member]]

+ References

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-Number 24
-IssueDate 2024-01-01
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-URIDate 2024-03-27

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of leases where the entity was the lessee in related party transactions. [Refer: Total for all related parties [member]]

+ References

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-URIDate 2024-03-27

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

- Definition

The number of shares issued by the entity.

+ References

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-URIDate 2024-03-27

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

- Definition

The amount of revenue arising from the sale of goods in related party transactions. [Refer: Revenue; Total for all related parties [member]]

+ References

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-Number 24
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-URIDate 2024-03-27

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of assets that represent a lessee's right to use an underlying asset for the lease term that do not meet the definition of investment property. Underlying asset is an asset that is the subject of a lease, for which the right to use that asset has been provided by a lessor to a lessee.

+ References

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-URIDate 2024-03-27

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of services received in related party transactions. [Refer: Total for all related parties [member]]

+ References

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-Number 24
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Details

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Period Type:

- Details

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- Details

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Related Party Disclosures - Additional Information (Details) € in Thousands, $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 USD ($)	Sep. 30, 2024 EUR (€) shares	Sep. 30, 2023 EUR (€)	Sep. 30, 2022 EUR (€)
Disclosure of transactions between related parties [line items]
Non-employee director cash compensation per year			€ 100
Right of use Assets			171,334	€ 122,984
Ockenfels
Disclosure of transactions between related parties [line items]
Lease payments			500	500	€ 500
Lease liability			1,300	1,700
Right of use Assets			1,200	1,700
Outstanding receivables			9,800	2,500
Outstanding payables			1,800
Management Investment Plan
Disclosure of transactions between related parties [line items]
Paid personal income taxes for the fully vested program	€ 11,400	$ 12.6
Other related parties [member]
Disclosure of transactions between related parties [line items]
Director compensation			€ 800
Shares issued \| shares			3,610
Cash Compensation			€ 100
Consulting fees and cost reimbursements			300	400	2,900
Sales			700	2,300	3,300
Marketing expenses			100	200	€ 500
Lease liability			200	100
Right of use Assets			200	€ 100
TRA liability			€ 359,900