Note D - Marketable Equity Securities - Unrealized Gains and Losses on Marketable Equity Securities (Details) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Gross unrealized gains | $ 19,591 | $ 21,362 |
| Gross unrealized losses | (939) | (1,085) |
| Net unrealized gain | $ 18,652 | $ 20,277 |