Note 9 - Debt, Credit Facility and Leases - Credit Facility (Details)	9 Months Ended
	Sep. 30, 2020
Maximum [Member]
Senior leverage ratio (debt secured by liens/EBITDA)	2.50
Leverage ratio (total debt less unencumbered cash/EBITDA)	4.00
Interest coverage ratio (EBITDA/interest expense)	3.00
New Facility [Member] | Minimum [Member]
Standby fee per annum on undrawn amounts	0.5625%
New Facility [Member] | Maximum [Member]
Standby fee per annum on undrawn amounts	1.00%
New Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Spread over the London Interbank Offered Rate	2.25%
New Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Spread over the London Interbank Offered Rate	4.00%
New Facility [Member] | Base Rate [Member] | Minimum [Member]
Spread over the London Interbank Offered Rate	1.25%
New Facility [Member] | Base Rate [Member] | Maximum [Member]
Spread over the London Interbank Offered Rate	3.00%