Note 4 - Debt - Leverage Ratios (Details)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2017
Maximum [Member]
Fixed Charge Coverage Ratio					0.75
Maximum [Member] | Forecast [Member]
Fixed Charge Coverage Ratio	1.15	1.05	0.95	0.85
Minimum [Member]
Fixed Charge Coverage Ratio					1
Minimum [Member] | Forecast [Member]
Fixed Charge Coverage Ratio	1	1	1	1