Investments (Fair Value Realized and Unrealized Gain (Losses)) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Net Investment Income [Line Items] | ||||
| Total | $ (24.9) | $ 64.4 | $ 188.3 | $ 175.5 |
| EdgeConneX | ||||
| Net Investment Income [Line Items] | ||||
| Total | 0.0 | 0.3 | 154.2 | 3.9 |
| ITV | ||||
| Net Investment Income [Line Items] | ||||
| Total | (16.0) | (20.9) | (22.1) | 58.9 |
| Lionsgate | ||||
| Net Investment Income [Line Items] | ||||
| Total | (29.0) | 7.7 | 14.6 | 0.4 |
| Televisa Univision | ||||
| Net Investment Income [Line Items] | ||||
| Total | 2.0 | (3.5) | 9.8 | (45.1) |
| Plume | ||||
| Net Investment Income [Line Items] | ||||
| Total | (2.7) | (0.4) | (9.5) | (13.4) |
| Vodafone | ||||
| Net Investment Income [Line Items] | ||||
| Total | 0.0 | 86.1 | 0.0 | 207.7 |
| Other, net | ||||
| Net Investment Income [Line Items] | ||||
| Total | $ 20.8 | $ (4.9) | $ 41.3 | $ (36.9) |