Note J - Fair Value of Financial Instruments - Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Cash and cash equivalents	$ 45,366	$ 24,685
Restricted cash	9,731	10,902
Note receivable	219	339
Total assets	55,316	35,926
Bank acceptance payable	15,482	12,337
Convertible senior notes	76,519	58,314
Total liabilities	92,001	70,651
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	45,366	24,685
Restricted cash	9,731	10,902
Note receivable	0	0
Total assets	55,097	35,587
Bank acceptance payable	0	0
Convertible senior notes	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	0
Restricted cash	0	0
Note receivable	219	339
Total assets	219	339
Bank acceptance payable	15,482	12,337
Convertible senior notes	76,519	58,314
Total liabilities	92,001	70,651
Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	0
Restricted cash	0	0
Note receivable	0	0
Total assets	0	0
Bank acceptance payable	0	0
Convertible senior notes	0	0
Total liabilities	$ 0	$ 0