Note 4 - Investment in Equity Securities (Details Textual) - USD ($) $ in Thousands			6 Months Ended	12 Months Ended
	Dec. 23, 2022	Jul. 02, 2022	Dec. 23, 2022	Dec. 31, 2022	Dec. 31, 2021
Payments to Acquire Equity Securities without Readily Determinable Fair Value				$ 4,700	$ (0)
Dynamic Cell Therapies, Inc. [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			19.00%
Dynamic Cell Therapies, Inc. [Member]
Additional Payment Needed for Preferred Stock Equity Interest If Agreement Not Reached		$ 2,000
Percentage of Equity Purchased If Agreement Not Reached		19.99%
Payments for Preferred Stock Equity Interest	$ 2,000
Payments to Acquire Equity Securities without Readily Determinable Fair Value			$ 4,700
Equity Securities without Readily Determinable Fair Value, Impairment Loss, Annual Amount				$ 0
Dynamic Cell Therapies, Inc. [Member]
Deposit on Purchase of Non-marketable Preferred Securities		$ 2,700