The following tables summarize the amount of unrealized losses, defined as the amount by which the amortized cost exceeds fair value, and the related fair value of investments with unrealized losses. The investments were segregated into two categories: those that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 or more months. The reference point for determining how long an investment was in an unrealized loss position was June 30, 2026. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of June 30, 2026 | | Less than 12 Months | | Greater than 12 Months | | Total | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | (In millions) | | Short-term investments | $ | — | | | $ | — | | | $ | 0.8 | | | $ | — | | | $ | 0.8 | | | $ | — | | | U.S. Treasuries | 2.0 | | | — | | | — | | | — | | | 2.0 | | | — | | | Municipal | 0.1 | | | — | | | — | | | — | | | 0.1 | | | — | | | Corporate | 40.2 | | | (0.5) | | | 2.1 | | | — | | | 42.2 | | | (0.5) | | | Mortgage and other asset-backed securities | 69.8 | | | (0.7) | | | 33.1 | | | (0.5) | | | 102.9 | | | (1.2) | | | Total debt securities | $ | 112.1 | | | $ | (1.2) | | | $ | 36.0 | | | $ | (0.5) | | | $ | 148.1 | | | $ | (1.7) | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of December 31, 2025 | | Less than 12 Months | | Greater than 12 Months | | Total | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | (In millions) | | Short-term investments | $ | — | | | $ | — | | | $ | 0.5 | | | $ | — | | | $ | 0.5 | | | $ | — | | | U.S. Treasuries | — | | | — | | | 0.8 | | | — | | | 0.8 | | | — | | | | | | | | | | | | | | | Corporate | 4.8 | | | — | | | — | | | — | | | 4.8 | | | — | | | Mortgage and other asset-backed securities | 28.8 | | | (0.1) | | | 18.8 | | | (0.2) | | | 47.6 | | | (0.3) | | | Total debt securities | $ | 33.5 | | | $ | (0.1) | | | $ | 20.2 | | | $ | (0.2) | | | $ | 53.7 | | | $ | (0.3) | |
|