Note D - Marketable Equity Securities - Unrealized Gains and Losses on Marketable Equity Securities (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Gross unrealized gains | $ 20,752 | $ 21,362 |
| Gross unrealized losses | (291) | (1,085) |
| Net unrealized gain | $ 20,461 | $ 20,277 |