Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2022	Sep. 06, 2022	Dec. 31, 2021
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
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		29,620,083
Entity Public Float			$ 41,047,675
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-39832
Entity Tax Identification Number	85-3622015
Entity Address, Address Line One	800 South Street
Entity Address, Address Line Two	Suite 230
Entity Address, City or Town	Waltham
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02453
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	Grant Thornton LLP
Auditor Firm ID	248
Auditor Location	Boston, Massachusetts
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