Form N-CSR Cover	12 Months Ended
Dec. 31, 2024
Shareholder Report [Line Items]
Document Type	N-CSR/A
Amendment Flag	true
Amendment Description	Amended filing for 3/07/2025 OBERWEIS NCSR.
Registrant Name	Oberweis Funds
Entity Central Index Key	0000803020
Entity Investment Company Type	N-1A
Document Period End Date	Dec. 31, 2024

Description of changes contained within amended document.

No definition available.

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Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

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- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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No definition available.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2

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One of: N-1A (Mutual Fund), N-1 (Open-End Separate Account with No Variable Annuities), N-2 (Closed-End Investment Company), N-3 (Separate Account Registered as Open-End Management Investment Company), N-4 (Variable Annuity UIT Separate Account), N-5 (Small Business Investment Company), N-6 (Variable Life UIT Separate Account), S-1 or S-3 (Face Amount Certificate Company), S-6 (UIT, Non-Insurance Product).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-T
-Number 232
-Section 313

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Form N-1A
-Section 27A
-Subsection d
-Paragraph 2
-Subparagraph instruction
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