Note 9 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions		12 Months Ended
	Dec. 06, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Lease, Expense		$ 1.0	$ 1.1	$ 1.1
Enma Sagastume v. Psychemedics Corporation [Member]
Litigation Settlement, Amount Awarded to Other Party	$ 1.2
Loss Contingency Accrual, Ending Balance			$ 1.2