Note 16 - Fair Value of Financial instruments - Financial Instruments Measured at Fair Value (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member]
Interest Rate Swaps	$ 0	$ 0
Fair Value, Inputs, Level 1 [Member] | Commodity Contract [Member]
Interest Rate Swaps	0	0
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Interest Rate Swaps	(1,224)	(2,834)
Fair Value, Inputs, Level 2 [Member] | Commodity Contract [Member]
Interest Rate Swaps	(167,743)	0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member]
Interest Rate Swaps	0	0
Fair Value, Inputs, Level 3 [Member] | Commodity Contract [Member]
Interest Rate Swaps	$ 0	$ 0