v3.26.1
Retirement Benefits - Net Periodic Benefit Cost (Details) - Pension Plan [Member] - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Defined Benefit Plan Disclosure [Line Items]    
Settlements   $ 82
United States [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Service cost $ 9 10
Interest cost 41 36
Expected return on plan assets (63) (55)
Settlements 0 82
Amortization of net loss 18 9
Amortization of prior service credit 0 0
Net periodic benefit cost/(income) 5 82
United Kingdom [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Service cost 1 1
Interest cost 30 29
Expected return on plan assets (47) (42)
Settlements 0 3
Amortization of net loss 16 15
Amortization of prior service credit 1 (1)
Net periodic benefit cost/(income) 1 5
Other Foreign Plans [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Service cost 3 3
Interest cost 7 6
Expected return on plan assets (12) (10)
Settlements 3 0
Amortization of net loss 0 0
Amortization of prior service credit 0 0
Net periodic benefit cost/(income) $ 1 $ (1)