Note 9 - Incentive Plans - Number of Shares Available for Grant Pursuant to Long-term Incentive Plan (Details) - shares	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Shares subject to awards issued under plan (in shares)	(13,449,061)		(11,517,228)	(9,983,727)
The 2020 Long-term Incentive Plan [Member]
Approved and authorized shares (in shares)		16,388,015	14,340,324
Shares subject to awards issued under plan (in shares)		(15,759,791)	(13,769,191)
Shares available for future grant (in shares)		628,224	571,133