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

No definition available.

Name:	dei_AmendmentFlag
Namespace Prefix:	dei_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

PCAOB issued Audit Firm Identifier

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
Document and Entity Information - USD ($) $ in Thousands	Jun. 30, 2025	Jun. 30, 2024	Aug. 26, 2025	Dec. 31, 2024
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Registrant Name	GREAT ELM GROUP, INC.
Entity Central Index Key	0001831096
Current Fiscal Year End Date	--06-30
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding			28,996,787
Entity Public Float				$ 26,595,541
Entity Small Business	true
Entity Emerging Growth Company	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity File Number	001-39832
Entity Tax Identification Number	85-3622015
Entity Address, Address Line One	3801 PGA Boulevard
Entity Address, Address Line Two	Suite 603
Entity Address, City or Town	Palm Beach Gardens
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33410
City Area Code	617
Local Phone Number	375-3006
Document Annual Report	true
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Auditor Name	Deloitte & Touche LLP	Grant Thornton LLP
Auditor Firm ID	34	248
Auditor Location	Boston, Massachusetts	Boston, Massachusetts
Documents Incorporated by Reference	Portions of the definitive proxy statement for the annual meeting of stockholders of the Registrant, to be filed with the Securities and Exchange Commission within 120 days of our fiscal year ended June 30, 2025, are incorporated by reference into Part III of this report.
Common Stock
Document Information [Line Items]
Title of each class	Common stock, par value $0.001 per share
Trading Symbol	GEG
Security Exchange Name	NASDAQ
7.25% Notes due 2027
Document Information [Line Items]
Title of each class	7.25% Notes due 2027
Trading Symbol	GEGGL
Security Exchange Name	NASDAQ