Note 7 - Long-term Debt - Maximum Total Leverage Ratio (Details)	Dec. 31, 2019
Four Fiscal Quarters Ended March 31, 2019 through December 31, 2019 [Member]
Maximum total leverage ratio	6.00
Four Fiscal Quarters Ended March 31, 2020 through December 31, 2020 [Member]
Maximum total leverage ratio	5.75
Four Fiscal Quarters Ended March 31, 2021 and Thereafter [Member]
Maximum total leverage ratio	5.50