Note 3 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%	21.00%
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority					$ (99)
National Tax Service of Korea [Member]
Income Taxes Receivable, Noncurrent	$ 255		$ 255			$ 349