Note 17 - Related Party Transactions (Details Textual) - USD ($)	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jul. 01, 2018
Equity Securities, FV-NI, Total	$ 14,300,000	$ 18,258,000
Payments to Acquire Short-Term Investments	6,000,000	(0)
Equity Securities, FV-NI, Realized Gain (Loss), Total	1,848,000	16,566,000
Other Accrued Liabilities, Current	1,831,000	1,345,000
Investment Owned, Fair Value	24,900,000
Realized Gain (Loss) on Principal Payment Proceeds	2,200,000	1,200,000
Retained Earnings (Accumulated Deficit), Total	36,302,000	33,833,000
Equity Securities, FV-NI, Cost	19,967,000	14,363,000
Investment Income, Net, Total	(6,174,000)	28,338,000
Accounts and Other Receivables, Net, Current	1,796,000	2,534,000
Equity Securities without Readily Determinable Fair Value, Amount	3,992,000	3,453,000
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount	187,000	1,561,000
Reclassified of Unrealized Gains Related to Investment From Accumulated Other Comprehensive Income (Loss) to Retained Earnings [Member]
Retained Earnings (Accumulated Deficit), Total			$ 3,200,000
HIVE Blockchain Technologies Ltd. [Member]
Investment Owned, Fair Value	11,100,000	25,100,000
Proceeds from Sale of Debt Securities, Available-for-Sale	3,000,000.0	1,400,000
Realized Gain (Loss) on Principal Payment Proceeds	2,200,000	1,200,000
Proceeds from Sale of Long-Term Investments		20,600,000
Equity Securities, FV-NI, Cost		2,400,000
Equity Securities, FV-NI, Realized Gain		15,000,000.0
Thunderbird Entertainment Group [Member]
Equity Securities, FV-NI, Total		2,700,000
Equity Securities, FV-NI, Realized Gain	1,900,000	936,000
The Sonar Company [Member]
Equity Securities without Readily Determinable Fair Value, Amount	362,000	100,000
Payments to Acquire Equity Securities Without Readily Determinable Fair Value	75,000
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount	187,000
Operating Lease, Lease Income, Total	15,000	0
Receivables From Mutual Funds [Member]
Receivables, Net, Current, Total	1,600,000	2,400,000
U S Global Investors Funds [Member]
Equity Securities, FV-NI, Total	12,800,000	7,300,000
Payments to Acquire Short-Term Investments	6,000,000.0
Investment Income, Dividends and Capital Gains	146,000	15,000
Equity Securities, FV-NI, Realized Gain (Loss), Total	0	0
Mutual Funds [Member]
Other Accrued Liabilities, Current	110,000
HIVE Blockchain Technologies Ltd. [Member]
Investment Income, Net, Total	1,600,000	368,000
Consulting Fees Income	120,000	40,000
Accounts and Other Receivables, Net, Current	$ 140,000	$ 40,000