v3.26.3
Benefit Plans (Tables)
 9 Months Ended
Sep. 30, 2026
Retirement Benefits [Abstract]  
Schedule of Components of Net Cost (Benefit) for Pension and Other Postretirement Plans
Components of net cost (benefit) for pension and other postretirement plans
Three months ended September 30,Nine months ended September 30,
($ in millions)2026202520262025
Pension benefits
Service cost$29 $28 $87 $79 
Interest cost59 58 176 177 
Expected return on plan assets(82)(77)(243)(233)
Costs and expenses6 9 20 23 
Remeasurement of projected benefit obligation(244)20 (283)128 
Remeasurement of plan assets222 (127)135 (158)
Remeasurement (gains) losses(22)(107)(148)(30)
Pension net benefit$(16)$(98)$(128)$(7)
Postretirement benefits
Service cost$— $— $— $— 
Interest cost1 2 5 6 
Amortization of prior service credit— (1)(1)(1)
Costs and expenses1 1 4 5 
Remeasurement of benefit obligation
(6)(1)(7)— 
Remeasurement (gains) losses(6)(1)(7)— 
Postretirement net (benefit) cost$(5)$— $(3)$5 
Pension and postretirement benefits
Costs and expenses$7 $10 $24 $28 
Remeasurement (gains) losses(28)(108)(155)(30)
Total net benefit$(21)$(98)$(131)$(2)
Schedule of Pension and Postretirement Benefits Remeasurement Gains and Losses
Pension and postretirement benefits remeasurement gains and losses
Three months ended September 30,Nine months ended September 30,
($ in millions)2026202520262025
Remeasurement of benefit obligation (gains) losses:
Discount rate$(274)$29 $(343)$93 
Other assumptions24 (10)53 35 
Remeasurement of plan assets (gains) losses222 (127)135 (158)
Remeasurement (gains) losses$(28)$(108)$(155)$(30)