Note 6 - Stockholders' Equity - Summary of Shares to be Issued (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Shares-to-be-issued, outstanding (in shares)	2,440,673	2,066,343
Granted in current period (in shares)	78,125	108,148
Issued in current period (in shares)	0	0
Shares-to be issued outstanding March 31, 2023 and 2022, respectively (in shares)	2,518,798	2,174,491