Note 9 - Debt, Credit Facility and Leases - Credit Facility (Details) - New Facility [Member]	6 Months Ended
	Jun. 30, 2020
Senior leverage ratio (debt secured by liens/EBITDA)	2.50
Leverage ratio (total debt less unencumbered cash/EBITDA) (1)	4.25	[1]
Interest coverage ratio (EBITDA/interest expense)	3.00
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%

[1] The leverage ratio changed to 4.00:1 effective July 1, 2020.