Note 5 - PNC Credit Facility - Summary of Quarterly Leverage Ratio (Details)	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Two Thousand Fourteen Credit Agreement [Member] | Scenario, Forecast [Member]
March 31, 2017	3.5	3.5	5	5	5	5.5	7	4.5	4.5	5.5