Non-Controlling Interests and Preferred Stock of Subsidiary - Summary of Preferred Stock Activity (Details) - shares	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Minority Interest [Line Items]
Balance, as of June 30, 2021	79,110
Issuance of Preferred Stock		79,110
Redemption of Preferred Stock	(6,000)
Balance, as of June 30, 2022	73,110	79,110
Great Elm Healthcare, LLC (HC LLC)
Minority Interest [Line Items]
Balance, as of June 30, 2021	44,100
Issuance of Preferred Stock		44,100
Redemption of Preferred Stock	(6,000)
Balance, as of June 30, 2022	38,100	44,100
Series A-1 Preferred Stock | Great Elm Healthcare, LLC (HC LLC)
Minority Interest [Line Items]
Balance, as of June 30, 2021	10,090
Issuance of Preferred Stock		10,090
Redemption of Preferred Stock	(6,000)
Balance, as of June 30, 2022	4,090	10,090
Series A-2 Preferred Stock | Great Elm Healthcare, LLC (HC LLC)
Minority Interest [Line Items]
Balance, as of June 30, 2021	34,010
Issuance of Preferred Stock		34,010
Balance, as of June 30, 2022	34,010	34,010
Forest Preferred Stock | Forest Investments, Inc. (Forest)
Minority Interest [Line Items]
Balance, as of June 30, 2021	35,010
Issuance of Preferred Stock		35,010
Balance, as of June 30, 2022	35,010	35,010