Note 9 - Incentive Plans - Number of Shares Available for Grant Pursuant to Long-term Incentive Plan (Details) - shares	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Awards issued under plan (in shares)	(9,976,227)	(9,983,727)	(9,705,495)
The 2020 Long-term Incentive Plan [Member]
Approved and authorized awards (in shares)	13,174,746
Awards issued under plan (in shares)	(11,607,006)
Awards available for future grant (in shares)	1,567,740