Note 4 - Fair Value Measurements - Investments (Details) - USD ($) $ in Thousands |
Sep. 30, 2021 |
Dec. 31, 2020 |
||
---|---|---|---|---|
Adjusted cost | [1] | $ 66,542 | $ 68,401 | |
Gross unrealized losses | [1] | (7) | (11) | |
Fair value | [1] | 66,549 | 68,390 | |
Fair value | [1] | (66,549) | (68,390) | |
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | ||||
Adjusted cost | [1] | 37,534 | 21,042 | |
Gross unrealized losses | [1] | 0 | 0 | |
Fair value | [1] | 37,534 | 21,042 | |
Fair value | [1] | (37,534) | (21,042) | |
Bank Time Deposits [Member] | Fair Value, Inputs, Level 2 [Member] | ||||
Adjusted cost | [1] | 0 | 5,458 | |
Gross unrealized losses | [1] | 0 | 0 | |
Fair value | [1] | 0 | 5,458 | |
Fair value | [1] | 0 | (5,458) | |
Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member] | ||||
Adjusted cost | [1] | 11,849 | 30,280 | |
Gross unrealized losses | [1] | (1) | (5) | |
Fair value | [1] | 11,848 | 30,275 | |
Fair value | [1] | (11,848) | (30,275) | |
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | ||||
Adjusted cost | [1] | 17,159 | 11,621 | |
Gross unrealized losses | [1] | (8) | (6) | |
Fair value | [1] | 17,167 | 11,615 | |
Fair value | [1] | $ (17,167) | $ (11,615) | |
|