Note 6 - Fair Value Measurement - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Corporate bonds	$ 102,972	$ 90,298
Investments in marketable equity securities	1,103	2,919
Foreign exchange contract	595	63
Fair Value, Inputs, Level 1 [Member]
Investments in marketable equity securities	1,103	2,919
Foreign exchange contract	0	0
Fair Value, Inputs, Level 2 [Member]
Investments in marketable equity securities	0	0
Foreign exchange contract	595	63
Fair Value, Inputs, Level 3 [Member]
Investments in marketable equity securities	0	0
Foreign exchange contract	0	0
Corporate Bonds [Member]
Corporate bonds	102,972	90,298
Corporate Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Corporate bonds	0	0
Corporate Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Corporate bonds	102,972	90,298
Corporate Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Corporate bonds	$ 0	$ 0