v3.26.3
Fair Value of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Assets    
Fixed income securities, at fair value $ 60,246 $ 59,115
Equity securities 10,172 8,398
Short-term investments 5,779 4,887
Other investments 1,080 1,114
Total assets at fair value 75,812 72,025
Counterparty and cash collateral netting (9) (1)
Total 76,936 73,291
Liabilities    
Preferred stock measured at cost 107 99
Equity method investments 608 466
Equity securities 9,200 8,026
U.S. government and agencies    
Assets    
Fixed income securities, at fair value 11,329 18,133
Municipal    
Assets    
Fixed income securities, at fair value 6,797 5,643
Foreign government    
Assets    
Fixed income securities, at fair value 1,666 1,460
ABS    
Assets    
Fixed income securities, at fair value 2,058 1,352
MBS    
Assets    
Fixed income securities, at fair value 2,022 2,126
Recurring basis    
Assets    
Fixed income securities, at fair value 60,246 59,115
Equity securities 9,457 7,833
Short-term investments 5,779 4,887
Other investments 8 11
Other investments (9) (1)
Other assets 129 147
Total assets at fair value 75,619 71,993
Counterparty and cash collateral netting (9) (1)
Liabilities    
Other liabilities (4) (3)
Other liabilities 4 19
Counterparty and cash collateral netting 4 19
Total recurring basis liabilities (4) (3)
Recurring basis | U.S. government and agencies    
Assets    
Fixed income securities, at fair value 11,329 18,133
Recurring basis | Municipal    
Assets    
Fixed income securities, at fair value 6,797 5,643
Recurring basis | Corporate - public    
Assets    
Fixed income securities, at fair value 23,778 19,919
Recurring basis | Corporate - privately placed    
Assets    
Fixed income securities, at fair value 12,596 10,482
Recurring basis | Foreign government    
Assets    
Fixed income securities, at fair value 1,666 1,460
Recurring basis | ABS    
Assets    
Fixed income securities, at fair value 2,058 1,352
Recurring basis | MBS    
Assets    
Fixed income securities, at fair value 2,022 2,126
Non-recurring basis    
Assets    
Total assets at fair value 193 32
Quoted prices in active markets for identical assets (Level 1)    
Assets    
Total assets at fair value 22,515 27,487
Quoted prices in active markets for identical assets (Level 1) | Recurring basis    
Assets    
Fixed income securities, at fair value 11,325 18,124
Equity securities 9,231 7,572
Short-term investments 1,959 1,791
Other investments 0 0
Other assets 0 0
Total assets at fair value 22,515 27,487
Liabilities    
Other liabilities (3) (2)
Total recurring basis liabilities (3) (2)
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | U.S. government and agencies    
Assets    
Fixed income securities, at fair value 11,325 18,124
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | Municipal    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | Corporate - public    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | Corporate - privately placed    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | Foreign government    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | ABS    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Recurring basis | MBS    
Assets    
Fixed income securities, at fair value 0 0
Quoted prices in active markets for identical assets (Level 1) | Non-recurring basis    
Assets    
Total assets at fair value 0 0
Significant other observable inputs (Level 2)    
Assets    
Total assets at fair value 52,544 44,023
Significant other observable inputs (Level 2) | Recurring basis    
Assets    
Fixed income securities, at fair value 48,503 40,683
Equity securities 208 239
Short-term investments 3,817 3,090
Other investments 16 11
Other assets 0 0
Total assets at fair value 52,544 44,023
Liabilities    
Other liabilities (5) (19)
Total recurring basis liabilities (5) (19)
Significant other observable inputs (Level 2) | Recurring basis | U.S. government and agencies    
Assets    
Fixed income securities, at fair value 4 9
Significant other observable inputs (Level 2) | Recurring basis | Municipal    
Assets    
Fixed income securities, at fair value 6,792 5,614
Significant other observable inputs (Level 2) | Recurring basis | Corporate - public    
Assets    
Fixed income securities, at fair value 23,766 19,907
Significant other observable inputs (Level 2) | Recurring basis | Corporate - privately placed    
Assets    
Fixed income securities, at fair value 12,419 10,295
Significant other observable inputs (Level 2) | Recurring basis | Foreign government    
Assets    
Fixed income securities, at fair value 1,666 1,460
Significant other observable inputs (Level 2) | Recurring basis | ABS    
Assets    
Fixed income securities, at fair value 1,889 1,330
Significant other observable inputs (Level 2) | Recurring basis | MBS    
Assets    
Fixed income securities, at fair value 1,967 2,068
Significant other observable inputs (Level 2) | Non-recurring basis    
Assets    
Total assets at fair value 0 0
Significant unobservable inputs (Level 3)    
Assets    
Total assets at fair value 762 516
Significant unobservable inputs (Level 3) | Recurring basis    
Assets    
Fixed income securities, at fair value 418 308
Equity securities 18 22
Short-term investments 3 6
Other investments 1 1
Other assets 129 147
Total assets at fair value 569 484
Liabilities    
Other liabilities 0 (1)
Total recurring basis liabilities 0 (1)
Significant unobservable inputs (Level 3) | Recurring basis | U.S. government and agencies    
Assets    
Fixed income securities, at fair value 0 0
Significant unobservable inputs (Level 3) | Recurring basis | Municipal    
Assets    
Fixed income securities, at fair value 5 29
Significant unobservable inputs (Level 3) | Recurring basis | Corporate - public    
Assets    
Fixed income securities, at fair value 12 12
Significant unobservable inputs (Level 3) | Recurring basis | Corporate - privately placed    
Assets    
Fixed income securities, at fair value 177 187
Significant unobservable inputs (Level 3) | Recurring basis | Foreign government    
Assets    
Fixed income securities, at fair value 0 0
Significant unobservable inputs (Level 3) | Recurring basis | ABS    
Assets    
Fixed income securities, at fair value 169 22
Significant unobservable inputs (Level 3) | Recurring basis | MBS    
Assets    
Fixed income securities, at fair value 55 58
Significant unobservable inputs (Level 3) | Non-recurring basis    
Assets    
Total assets at fair value 193 32
Reported to NAV    
Assets    
Investments reported at NAV 1,124 1,266
Liabilities    
Equity securities 608 466
Limited partnerships $ 516 $ 800