v3.26.1
Fair Value - Rollforward of Level 3 assets and liabilities (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period $ (14) $ (34) $ (18) $ (73)
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 1 2
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 (2) 0 (2)
Purchases, issuances, sales and settlements        
Purchases 0 0 0 0
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 16 3 53
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period (14) (20) (14) (20)
Available for sale | Structured securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period [2] 29 0 17 0
Total gains or (losses) (realized/unrealized) - included in earnings [1],[2] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income [2] 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases [2] 5 14 9 14
Issuances [2] 0 0 0 0
Sales [2] 0 0 0 0
Settlements [2] (4) (2) (5) (2)
Transfers in and/or out of Level 3 [2] 0 5 9 5
Balance at end of period [2] 30 17 30 17
Available for sale | Corporate bonds        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 116 150 128 97
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income (2) 0 (2) 0
Purchases, issuances, sales and settlements        
Purchases 1 0 1 0
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements (1) (5) (42) (22)
Transfers in and/or out of Level 3 0 0 29 70
Balance at end of period 114 145 114 145
Fair value option | Other investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 249 206 232 189
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 64 44 90 96
Issuances 0 0 0 0
Sales (3) (3) (3) (3)
Settlements (41) (39) (60) (74)
Transfers in and/or out of Level 3 3 0 13 0
Balance at end of period 272 208 272 208
Fair value option | Short term investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 46 29 40 33
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 25 18 46 24
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements (27) (2) (43) (12)
Transfers in and/or out of Level 3 0 0 1 0
Balance at end of period 44 45 44 45
Fair value option | Equity securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 4 4 5 4
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 1 (1) 1
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 0 0 0 0
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 0 0 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period 4 5 4 5
Equity securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 9 7 9 7
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 (1) 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 1 1 2 1
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 0 0 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period $ 10 $ 8 $ 10 $ 8
[1] Gains or losses were included in net realized gains (losses).
[2] Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.