REVENUE (Details Narrative) - USD ($)	12 Months Ended
May 31, 2022	May 31, 2021
Disaggregation of Revenue [Line Items]
Unrecognized deferred revenue	$ 5,329,047	$ 6,430,607
Recognized revenue	14,662,060	5,697,315
Pallets [Member]
Disaggregation of Revenue [Line Items]
Customer advances	$ 13,560,500	$ 8,334,755
Canada and Mexico [Member]
Disaggregation of Revenue [Line Items]
Sales revenue percent	1.45%	0.92%

Revenue from contract with customer sales revenue percentage.

No definition available.

Name:	GLGI_RevenueFromContractWithCustomerSalesRevenuePercentage
Namespace Prefix:	GLGI_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrecognized deferred revenue.

+ References

No definition available.

+ Details

Name:	GLGI_UnrecognizedDeferredRevenue
Namespace Prefix:	GLGI_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130549-203045

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredRevenueRevenueRecognized1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_ProductOrServiceAxis=GLGI_PalletsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=GLGI_CanadaandMexicoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: