Our financial instruments measured at fair value on a recurring basis at September 30, 2025, were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | Observable Inputs | | Directly or Indirectly Observable Inputs | | Unobservable Inputs | | Total | | (Level 1) | | (Level 2) | | (Level 3) | | | | | | | | | | | (In millions) | | Corporate debt securities | $ | 2,600 | | | $ | — | | | $ | 2,600 | | | $ | — | | | Mortgage-backed securities | 982 | | | — | | | 982 | | | — | | | Asset-backed securities | 396 | | | — | | | 396 | | | — | | | Municipal securities | 178 | | | — | | | 178 | | | — | | | U.S. Treasury notes | 22 | | | — | | | 22 | | | — | | | | | | | | | | | | | | | | | | | | | | | | | | Other | 48 | | | — | | | 48 | | | — | | | Total assets | $ | 4,226 | | | $ | — | | | $ | 4,226 | | | $ | — | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Our financial instruments measured at fair value on a recurring basis at December 31, 2024, were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | Observable Inputs | | Directly or Indirectly Observable Inputs | | Unobservable Inputs | | Total | | (Level 1) | | (Level 2) | | (Level 3) | | | | | | | | | | | (In millions) | | Corporate debt securities | $ | 2,744 | | | $ | — | | | $ | 2,744 | | | $ | — | | | Mortgage-backed securities | 914 | | | — | | | 914 | | | — | | | Asset-backed securities | 431 | | | — | | | 431 | | | — | | | Municipal securities | 183 | | | — | | | 183 | | | — | | | U.S. Treasury notes | 5 | | | — | | | 5 | | | — | | | | | | | | | | | | | | | | | | | Other | 48 | | | — | | | 48 | | | — | | | Total assets | $ | 4,325 | | | $ | — | | | $ | 4,325 | | | $ | — | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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