v3.26.1
Shareholders' equity AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other comprehensive income (loss), before income tax $ 94 $ 1,627 $ (812) $ 2,674        
Other Comprehensive Income (Loss), Tax 26 33 (115) 76        
Other Comprehensive Income (Loss), Net of Tax 68 1,594 (697) 2,598        
Total shareholders' equity 80,845 74,447 80,845 74,447   $ 79,779    
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity (3,282) (2,772) (3,282) (2,772) $ (3,611) (1,997) $ (3,704) $ (4,552)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Including Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), before Reclassifications, before Tax 276 918 (1,663) 1,761        
Net Realized Gains (Losses) Reclassified from AOCI (81) (68) (194) (126)        
Other comprehensive income (loss), before income tax 357 986 (1,469) 1,887        
Other Comprehensive Income (Loss), Tax 21 50 (189) 111        
Other Comprehensive Income (Loss), Net of Tax 336 936 (1,280) 1,776        
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax 7 4 5 (4)        
AOCI, Liability for Future Policy Benefit, Parent                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity (164) (746) (164) (746) (27) (344) (645) (539)
AOCI, Liability for Future Policy Benefit, Including Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other comprehensive income (loss), before income tax (145) (130) 241 (252)        
Other Comprehensive Income (Loss), Tax 8 (9) 69 (21)        
Other Comprehensive Income (Loss), Net of Tax (153) (121) 172 (231)        
AOCI, Liability for Future Policy Benefit, Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax (16) (20) (8) (24)        
AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, Parent                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity (12) (12) (12) (12) (13) (23) (13) (16)
AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, Including Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other comprehensive income (loss), before income tax 1 1 13 5        
Other Comprehensive Income (Loss), Tax 0 0 2 1        
Other Comprehensive Income (Loss), Net of Tax 1 1 11 4        
AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax 0 0 0 0        
Cumulative Foreign Currency Translation Adjustment [Member]                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity (3,015) (2,919) (3,015) (2,919) (2,778) (3,135) (3,685) (4,025)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), before Reclassifications, before Tax (147) 803 390 1,170        
Net Realized Gains (Losses) Reclassified from AOCI 11 7 20 15        
Other comprehensive income (loss), before income tax (158) 796 370 1,155        
Other Comprehensive Income (Loss), Tax (10) (3) (4) 9        
Other Comprehensive Income (Loss), Net of Tax (148) 799 374 1,146        
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax 89 33 254 40        
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity (27) (40) (27) (40) (61) (58) (22) 50
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), before Reclassifications, before Tax 16 141 (27) 115        
Net Realized Gains (Losses) Reclassified from AOCI (27) 164 (66) 229        
Other comprehensive income (loss), before income tax 43 (23) 39 (114)        
Other Comprehensive Income (Loss), Tax 9 (5) 8 (24)        
Other Comprehensive Income (Loss), Net of Tax 34 (18) 31 (90)        
Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax 0 0 0 0        
Postretirement Benefit Liability Adjustment [Member]                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Total shareholders' equity 577 431 577 431 579 582 434 438
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other comprehensive income (loss), before income tax (4) (3) (6) (7)        
Other Comprehensive Income (Loss), Tax (2) 0 (1) 0        
Other Comprehensive Income (Loss), Net of Tax (2) (3) (5) (7)        
Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax 0 0 0 0        
Accumulated Other Comprehensive Income (Loss) [Member]                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Other Comprehensive Income (Loss), Net of Tax (12) 1,577 (948) 2,586        
Total shareholders' equity $ (5,923) $ (6,058) $ (5,923) $ (6,058) $ (5,911) $ (4,975) $ (7,635) $ (8,644)