v3.26.3
Pension Plans, Retirement Benefits and Savings Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Pension Plans [Member]        
Defined benefit plan disclosure        
Service cost $ 30 $ 28 $ 90 $ 85
Interest cost on benefit obligation 42 44 127 132
Expected return on plan assets (74) (71) (223) (211)
Net periodic benefit cost (benefit), amortization of unrecognized prior service benefit 0 0 0 0
Net periodic benefit cost (benefit), amortization of unrecognized net actuarial (gain) loss 1 4 3 11
Total non-service cost (benefit) (31) (23) (93) (68)
Net periodic benefit cost (benefit) (1) 5 (3) 17
Pension Plans [Member] | Income Statement Location [Axis]: us-gaap:PolicyholderBenefitsAndClaimsIncurredNet        
Defined benefit plan disclosure        
Service cost 11 11 34 33
Total non-service cost (benefit) (12) (9) (35) (26)
Pension Plans [Member] | Income Statement Location [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense        
Defined benefit plan disclosure        
Service cost 19 17 56 52
Total non-service cost (benefit) (19) (14) (58) (42)
Postretirement Benefit Plans [Member]        
Defined benefit plan disclosure        
Service cost 0 0 0 0
Interest cost on benefit obligation 1 1 2 2
Expected return on plan assets 0 0 0 0
Net periodic benefit cost (benefit), amortization of unrecognized prior service benefit 0 0 (1) (1)
Net periodic benefit cost (benefit), amortization of unrecognized net actuarial (gain) loss (3) (3) (8) (9)
Total non-service cost (benefit) (2) (2) (7) (8)
Net periodic benefit cost (benefit) (2) (2) (7) (8)
Postretirement Benefit Plans [Member] | Income Statement Location [Axis]: us-gaap:PolicyholderBenefitsAndClaimsIncurredNet        
Defined benefit plan disclosure        
Service cost 0 0 0 0
Total non-service cost (benefit) (1) (1) (3) (3)
Postretirement Benefit Plans [Member] | Income Statement Location [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense        
Defined benefit plan disclosure        
Service cost 0 0 0 0
Total non-service cost (benefit) $ (1) $ (1) $ (4) $ (5)