v3.25.2
Long-duration insurance contracts - Summary of changes in discounted present values of expected future policy benefits and expected future net premiums (Detail) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]    
Balance at June 30 $ 17,865 $ 17,500
Periodic Payment Annuity [Member]    
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]    
Balance at beginning of year 10,276 11,212
Balance at beginning of year at original discount rate 11,757 11,681
Effect of actual versus expected experience (20) 4
Change in benefits, net (240) (235)
Interest accrual 277 273
Foreign currency effect 136 15
Ending balance at original discount rate 11,910 11,738
Effect of changes in discount rate assumptions (1,453) (1,360)
Expected future policy benefits at June 30 10,457 10,378
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]    
Balance at June 30 10,457 10,378
Liabilities for future policy benefits at June 30, net of reinsurance recoverables 10,457 10,378
Life and Health [Member]    
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]    
Balance at beginning of year 43,784 52,665
Balance at beginning of year at original discount rate 55,170 65,871
Effect of cash flow assumption changes (98) (324)
Effect of actual versus expected experience 246 (12,836)
Change in benefits, net (887) (943)
Interest accrual 646 575
Foreign currency effect 1,489 (459)
Ending balance at original discount rate 56,566 51,884
Effect of changes in discount rate assumptions (12,232) (12,739)
Expected future policy benefits at June 30 44,334 39,145
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]    
Balance at beginning of year 39,294 46,916
Balance at beginning of year at original discount rate 49,500 58,731
Effect of cash flow assumption changes (66) (326)
Effect of actual versus expected experience 204 (11,225)
Change in premiums, net (884) (876)
Interest accrual 579 507
Foreign currency effect 1,395 (436)
Ending balance at original discount rate 50,728 46,375
Effect of changes in discount rate assumptions (10,898) (11,397)
Expected future net premiums at June 30 39,830 34,978
Balance at June 30 4,504 4,167
Reinsurance recoverables (51) (49)
Liabilities for future policy benefits at June 30, net of reinsurance recoverables $ 4,453 $ 4,118