Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	497
Document Period End Date	dei_DocumentPeriodEndDate	Feb. 28, 2018
Registrant Name	dei_EntityRegistrantName	GMO TRUST
Central Index Key	dei_EntityCentralIndexKey	0000772129
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	May 17, 2018
Document Effective Date	dei_DocumentEffectiveDate	May 18, 2018
Prospectus Date	rr_ProspectusDate	Jun. 30, 2017
GMO Benchmark-Free Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GBMFX
GMO Benchmark-Free Allocation Fund \| Class IV
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GBMBX
GMO Global Asset Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GMWAX
GMO Global Equity Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GMGEX
GMO Global Developed Equity Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GWOAX
GMO International Equity Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GIEAX
GMO International Developed Equity Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GIOTX
GMO Benchmark-Free Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GBFFX
GMO Implementation Fund \| GMO Implementation Fund
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GIMFX
GMO Risk Premium Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GMRPX
GMO Risk Premium Fund \| Class IV
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GMRVX
GMO Risk Premium Fund \| Class VI
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GMOKX
GMO Strategic Opportunities Allocation Fund \| Class III
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GBATX

If the value is true, then the document is an amendment to previously-filed/accepted document.

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

The date when a document, upon receipt and acceptance, becomes officially effective, in CCYY-MM-DD format. Usually it is a system-assigned date time value, but it may be declared by the submitter in some cases.

+ References

No definition available.

+ Details

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- Definition

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

+ References

No definition available.

+ Details

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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".

+ References

No definition available.

+ Details

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- Definition

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

+ References

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

+ Details

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- Definition

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

+ References

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

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- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

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Data Type:	xbrli:normalizedStringItemType
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- Definition

The date of the prospectus.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 1
-Subsection a
-Paragraph 3

+ Details

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Namespace Prefix:	rr_
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- References

No definition available.

+ Details

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