Note 9 - Incentive Plans - Number of Shares Available for Grant Pursuant to Long-term Incentive Plan (Details) - shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Aug. 21, 2020
Awards issued under plan (in shares)	(11,517,228)	(9,983,727)	(9,705,495)	0
The 2020 Long-term Incentive Plan [Member]
Approved and authorized awards (in shares)	14,340,324	12,376,766
Awards issued under plan (in shares)	(13,769,191)	(11,614,506)
Awards available for future grant (in shares)	571,133	762,260