Note 4 - Derivative Instruments and Hedging Activities (Details Textual) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Mar. 31, 2020	Jun. 30, 2022 USD ($)	Mar. 31, 2022	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2017	Dec. 31, 2021 USD ($)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Total		$ 7,129		$ (2,752)	$ 25,857	$ 12,243
Derivative Assets (Liabilities), Net Fair Value of Derivative Contracts, Excluding Impact of Credit Risk				33,682		33,682		$ (2,148)
Commodity Contract [Member]
Derivative, Number of Instruments Held, Total								0
Interest Rate Swap [Member]
Number of New Contracts Entered	3		11				20
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Total		$ 7,129		$ 2,752	$ 25,857	$ 12,243