v3.26.1
Retirement Benefits - Net Periodic Benefit Cost (Details) - Pension Plan [Member] - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Defined Benefit Plan Disclosure [Line Items]          
Settlements         $ 82
United States [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Service cost $ 8 $ 10   $ 17 20
Interest cost 42 32   83 68
Expected return on plan assets (63) (51)   (126) (106)
Settlements 0 0 $ 82 0 82
Amortization of net loss 18 7   36 16
Amortization of prior service credit 0 0   0 0
Net periodic benefit cost/(income) 5 (2)   10 80
United Kingdom [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Service cost 2 2   3 3
Interest cost 30 31   60 60
Expected return on plan assets (48) (45)   (95) (87)
Settlements 0 0   0 3
Amortization of net loss 16 16   32 31
Amortization of prior service credit 1 (1)   2 (2)
Net periodic benefit cost/(income) 1 3   2 8
Other Foreign Plans [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Service cost 3 4   6 7
Interest cost 7 7   14 13
Expected return on plan assets (12) (12)   (24) (22)
Settlements 2 0   5 0
Amortization of net loss 0 0   0 0
Amortization of prior service credit 0 0   0 0
Net periodic benefit cost/(income) $ 0 $ (1)   $ 1 $ (2)