v3.26.1
Fair Value Measurements - Financial Instruments on a Recurring Basis (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale $ 3,937 $ 4,008
Total assets 3,937 4,008
Corporate debt securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 2,404 2,465
Mortgage-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 964 953
Asset-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 347 364
Municipal securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 156 159
U.S. Treasury notes    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 20 20
Other    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 46 47
(Level 1)    
Fair value of assets measured on recurring basis    
Total assets 0 0
(Level 1) | Corporate debt securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 1) | Mortgage-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 1) | Asset-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 1) | Municipal securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 1) | U.S. Treasury notes    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 1) | Other    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 2)    
Fair value of assets measured on recurring basis    
Total assets 3,937 4,008
(Level 2) | Corporate debt securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 2,404 2,465
(Level 2) | Mortgage-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 964 953
(Level 2) | Asset-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 347 364
(Level 2) | Municipal securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 156 159
(Level 2) | U.S. Treasury notes    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 20 20
(Level 2) | Other    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 46 47
(Level 3)    
Fair value of assets measured on recurring basis    
Total assets 0 0
(Level 3) | Corporate debt securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 3) | Mortgage-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 3) | Asset-backed securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 3) | Municipal securities    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 3) | U.S. Treasury notes    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale 0 0
(Level 3) | Other    
Fair value of assets measured on recurring basis    
Debt securities, available-for-sale $ 0 $ 0