Income Taxes - Additional Information (Details) $ in Millions	12 Months Ended
Jun. 30, 2026 USD ($)
Income Taxes [Line Items]
Federal net operating loss carryforwards	$ 13.4
Massachusetts
Income Taxes [Line Items]
Operating loss carryforward for state income tax	$ 14.0
Minimum \| Massachusetts
Income Taxes [Line Items]
Operating loss carryforwards expiration period	2037
Maximum \| Massachusetts
Income Taxes [Line Items]
Operating loss carryforwards expiration period	2046
Federal
Income Taxes [Line Items]
Net operating loss carryforwards, not subject to expiration	$ 11.9
Federal \| Minimum
Income Taxes [Line Items]
Operating loss carryforwards expiration period	2027
Federal \| Maximum
Income Taxes [Line Items]
Operating loss carryforwards expiration period	2038
Federal \| Expire in Fiscal Years 2027 Through 2038
Income Taxes [Line Items]
Net operating loss carryforwards, subject to expiration	$ 1.5

Income Taxes [Line Items]

No definition available.

Name:	geg_IncomeTaxesLineItems
Namespace Prefix:	geg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating loss carry forwards expiration year , in CCYY format.

+ References

No definition available.

+ Details

Name:	geg_OperatingLossCarryForwardsExpirationYear
Namespace Prefix:	geg_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are not subject to expiration dates.

+ References

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

+ References

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

+ References

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=geg_ExpireInFiscalYearsTwoThousandTwentySevenThroughTwoThousandThirtyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: