Note 16 - Segment Information - Total Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Segment Assets	$ 2,554,838	$ 2,693,802	$ 2,723,235
Cash and Other Investments	32,660		104,344
Deferred Tax Assets	101,639	$ 103,505	91,772
Operating Segments [Member] | Reportable Segments [Member]
Segment Assets	1,878,350		2,014,381
Operating Segments [Member] | All Other Segment [Member]
Segment Assets	$ 542,189		$ 512,738