Note 4 - Investments - Cash Flows (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Investments, net | $ (166.4) | $ (42.2) |
| Seeded Investment Products [Member] | ||
| Purchases and settlements | (348.1) | (103.5) |
| Sales, settlements and maturities | 40.4 | 39.4 |
| Investments, net | (307.7) | (64.1) |
| Securities Investment [Member] | ||
| Purchases and settlements | (267.8) | (114.8) |
| Sales, settlements and maturities | 101.4 | 72.6 |
| Investments, net | $ (166.4) | $ (42.2) |