Document and Entity Information	Total
Prospectus:
Document Type	497
Document Period End Date	Feb. 01, 2022
Entity Registrant Name	HARRIS ASSOCIATES INVESTMENT TRUST
Entity Central Index Key	0000872323
Entity Inv Company Type	N-1A
Amendment Flag	false
Document Creation Date	Feb. 01, 2022
Document Effective Date	Feb. 01, 2022
Prospectus Date	Jan. 28, 2022
Oakmark International Small Cap Fund \| Investor Class
Prospectus:
Trading Symbol	OAKEX
Oakmark International Small Cap Fund \| Advisor Class
Prospectus:
Trading Symbol	OAYEX
Oakmark International Small Cap Fund \| Institutional Class
Prospectus:
Trading Symbol	OANEX
Oakmark International Small Cap Fund \| R6 Class
Prospectus:
Trading Symbol	OAZEX

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The date the document was made available and submitted, in YYYY-MM-DD format. The date of submission, date of acceptance by the recipient, and the document effective date are all potentially different.

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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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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
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-Name Regulation 12B
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The date of the prospectus.

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Prospectus Table.

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