v3.25.2
Accumulated other comprehensive income (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance $ 649,368  
Ending Balance 667,989  
Unrealized investment gains (losses) [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance 117 $ 190
Other comprehensive income 129 (22)
Ending Balance 246 168
Foreign currency translation [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance (7,039) (5,393)
Other comprehensive income 1,521 (747)
Ending Balance (5,518) (6,140)
Long duration insurance contracts [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance 2,015 1,353
Other comprehensive income 118 684
Ending Balance 2,133 2,037
Defined benefit pension plans [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance 1,148 (97)
Other comprehensive income (87) 1
Ending Balance 1,061 (98)
Other AOCI transactions [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance 175 184
Other comprehensive income 8 (6)
Ending Balance 183 178
Accumulated other comprehensive income [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance (3,584) (3,763)
Other comprehensive income 1,689 (92)
Ending Balance $ (1,895) $ (3,855)