Note 7 - Credit Losses - Impact of ASC 326 (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Allowance for Credit Losses on Receivables			$ 2,811
Trade Accounts Receivable [Member]
Allowance for Credit Losses on Receivables	$ 4,597	$ 4,426	2,100
Other Non-trade Contractual Arrangements [Member]
Allowance for Credit Losses on Receivables	$ 6,948	$ 3,524	711
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for Credit Losses on Receivables			7,218
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Trade Accounts Receivable [Member]
Allowance for Credit Losses on Receivables			3,051
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Other Non-trade Contractual Arrangements [Member]
Allowance for Credit Losses on Receivables			4,167
Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for Credit Losses on Receivables			4,407
Cumulative Effect, Period of Adoption, Adjustment [Member] | Trade Accounts Receivable [Member]
Allowance for Credit Losses on Receivables			951
Cumulative Effect, Period of Adoption, Adjustment [Member] | Other Non-trade Contractual Arrangements [Member]
Allowance for Credit Losses on Receivables			$ 3,456