Non-Controlling Interests and Redeemable Preferred Stock of Subsidiaries - Summary of Non-controlling Interests Balance on Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Net income (loss)
Total net (loss) income attributable to non-controlling interest	$ (226)	$ (50)	$ 159
Great Elm Healthcare, LLC (HC LLC)
Net income (loss)
Temporary equity	(686)	752	(377)
Permanent equity	(686)	752	(377)
Total net (loss) income attributable to non-controlling interest	(1,372)	1,504	(754)
GEC GP
Net income (loss)
Permanent equity	(3)		(7)
Consolidated Fund
Net income (loss)
Permanent equity	(95)	(8)	(146)
Forest
Net income (loss)
Permanent equity	$ 1,244	$ (1,546)	$ 1,066