Note 9 - Equity Method Investment - TEL's Summarized Financial Information - Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Total Assets	$ 912,684	$ 881,640
Total Liabilities	584,191	531,529
Total Equity	328,493	350,111
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Total Assets	360,538	374,591
Total Liabilities	306,132	318,743
Total Equity	$ 54,406	$ 55,848