Note 7 - Income Taxes - Changes in Valuation Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Balance at the beginning of the period	$ 829,087	$ 512,711	$ 443,398
Additions attributable to the Merger	0	187,319	0
Additions not attributable to the Merger	146,451	160,299	72,025
Reductions	(94,252)	(31,242)	(2,712)
Balance at end of period	$ 881,286	$ 829,087	$ 512,711