Note 13 - Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended					6 Months Ended		12 Months Ended
	May 10, 2023	Feb. 28, 2024	Feb. 28, 2023	Feb. 28, 2022	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2022	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	May 31, 2021	Mar. 11, 2013
Common Stock, Dividends, Per Share, Declared (in dollars per share)					$ 0.075	$ 0.075	$ 0.075	$ 0.075		$ 0.15	$ 0.15
Share Repurchase Program, Authorized, Amount														$ 7,000
Treasury Stock, Common, Value					$ 42,567					$ 42,567		$ 37,486
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)					0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)					0					0
Payments to Acquire Interest in Subsidiaries and Affiliates										$ (0)	$ 1,200
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount					$ 4,700					$ 4,700
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)										2 years 1 month 6 days
Deferred Stock Units [Member] | Deferred Compensation, Share-Based Payments [Member]
Deferred Compensation Arrangement with Individual, Shares Issued (in shares)				290,000
Genie Energy International Corporation ("GEIC") [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner		0.50%
Payments to Acquire Interest in Subsidiaries and Affiliates		$ 1,200
Common Class B [Member]
Stock Repurchased During Period, Shares (in shares)					158,874		118,758			286,137	368,758
Stock Repurchased During Period, Value					$ 2,700		$ 1,800			$ 4,600	$ 5,900
Share Repurchase Program, Remaining Authorized, Number of Shares (in shares)					3,700,000					3,700,000
Treasury Stock, Common, Value					$ 4,200					$ 4,200		3,800
Treasury Stock, Value, Acquired, Cost Method										$ 42,600		$ 37,500
Shares Acquired, Average Cost Per Share (in dollars per share)										$ 10.27		$ 9.79
Common Class B [Member] | Restricted Stock [Member] | Deferred Compensation, Share-Based Payments [Member]
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)			290,000						290,000
Common Class B [Member] | The 2021 Plan [Member] | Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)													1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)	500,000
Common Class B [Member] | Howard Jonas [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)		126,176
Stock Issued During Period, Shares, New Issues (in shares)		49,632
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation (in shares)		76,544
O 2025 Q3 Dividends [Member]
Common Stock, Dividends, Per Share, Declared (in dollars per share)					$ 0.075
Dividends Payable, Date Declared					Jul. 31, 2025
Dividends Payable, Date to be Paid					Aug. 19, 2025
Dividends Payable, Date of Record					Aug. 11, 2025