Note 9 - Debt, Credit Facility and Leases - Credit Facility (Details) - New Facility [Member]	3 Months Ended
	Mar. 31, 2020
Minimum [Member]
Standby fee per annum on undrawn amounts	0.5625%
Maximum [Member]
Standby fee per annum on undrawn amounts	1.00%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Spread over the London Interbank Offered Rate	2.25%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Spread over the London Interbank Offered Rate	4.00%
Base Rate [Member] | Minimum [Member]
Spread over the London Interbank Offered Rate	1.25%
Base Rate [Member] | Maximum [Member]
Spread over the London Interbank Offered Rate	3.00%