Note 5 - Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Contingent consideration receivable	$ 682,000	$ 0
Fair Value, Recurring [Member]
Contingent consideration receivable	682,000
Money Market Funds [Member] | Fair Value, Recurring [Member]
Money market funds	3,295	58,242
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Contingent consideration receivable	0
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Money market funds	3,295	58,242
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Contingent consideration receivable	0
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Money market funds	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Contingent consideration receivable	682,000
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Money market funds	$ 0	$ 0