Note 1 - General and Basis of Presentation - Cash and Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 267,802	$ 448,252	$ 197,309
Restricted cash and cash equivalents	88,498	88,526	92,233
Total Cash and cash equivalents and restricted cash and cash equivalents	$ 356,300	$ 536,778	$ 289,542	$ 153,110