Non-Controlling Interests and 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, 2021	Mar. 31, 2022	Mar. 31, 2021
Net income (loss)
Total	$ (226)	$ (158)	$ 159	$ (862)
DME, Inc.
Net income (loss)
Temporary equity		(509)		(846)
Permanent equity		(509)		(846)
Total		(1,018)		(1,692)
Great Elm Healthcare, LLC (HC LLC)
Net income (loss)
Temporary equity	(686)		(377)
Permanent equity	(686)		(377)
Total	(1,372)		(754)
GP Corp.
Net income (loss)
Permanent equity		(26)		(86)
GEC GP
Net income (loss)
Permanent equity	(3)		(7)
Consolidated Fund
Net income (loss)
Permanent equity	(95)	(148)	(146)	(148)
Forest
Net income (loss)
Permanent equity	$ (1,244)	1,019	$ 1,066	1,019
FM Holdings
Net income (loss)
Permanent equity		$ 15		$ 45