v3.26.1
Long-duration insurance contracts - Summary of Other Information Relating to Long-Duration Insurance Liabilities (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Jun. 30, 2025
Periodic Payment Annuity [Member]    
Liability for Future Policy Benefit, Activity [Line Items]    
Undiscounted expected future benefits $ 32,384 $ 30,670
Weighted average discount rate 5.90% 5.70%
Weighted average accretion rate 4.80% 4.80%
Weighted average duration (in years) 16 years 16 years
Life and Health [Member]    
Liability for Future Policy Benefit, Activity [Line Items]    
Undiscounted expected future gross premiums $ 114,003 $ 103,580
Discounted expected future gross premiums 67,028 60,951
Undiscounted expected future benefits $ 101,866 $ 94,173
Weighted average discount rate 5.40% 5.20%
Weighted average accretion rate 2.70% 2.70%
Weighted average duration (in years) 14 years 13 years