Note 6 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Accrued employee benefit plan costs	$ 7,673	$ 6,678
Stock based compensation	3,178	1,838
Net operating losses	134,280	183,004
Tax credit carryforwards	413,873	413,089
Disallowed business interest expense carryforward	15,556	14,764
Capital loss carryforward	5,261	5,607
Other	4,273	7,195
Gross deferred tax assets	584,094	632,175
Less valuation allowance	(532,994)	(591,720)
Net deferred tax assets	51,100	40,455
Depreciation and amortization	(45,856)	(40,294)
Outside basis difference deferred tax liability	(2,891)	(2,891)
Foreign interest withholding tax	(1,512)	(1,154)
Other	(290)	1,628
Gross deferred tax liabilities	(50,549)	(42,711)
Net deferred tax assets (liabilities)	$ 551
Net deferred tax assets (liabilities)		$ (2,256)