Note 1 - Business and Significant Accounting Policies - Cash and Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents	$ 71,173	$ 98,802	$ 47,818
Restricted cash and cash equivalents	81,937	78,693	48,825
Total cash and cash equivalents and restricted cash and cash equivalents	$ 153,110	$ 177,495	$ 96,643	$ 264,476