v3.25.2
Benefit Plans (Tables)
 6 Months Ended
Jun. 30, 2025
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 June 30,Six months ended June 30,
($ in millions)2025202420252024
Pension benefits
Service cost (1)
$26 $(7)$51 $26 
Interest cost59 58 119 116 
Expected return on plan assets(78)(76)(156)(153)
Costs and expenses7 (25)14 (11)
Remeasurement of projected benefit obligation55 (68)108 (93)
Remeasurement of plan assets(54)60 (31)85 
Remeasurement (gains) losses1 (8)77 (8)
Pension net cost (benefit)$8 $(33)$91 $(19)
Postretirement benefits
Service cost$— $— $— $— 
Interest cost2 3 4 5 
Amortization of prior service credit— (1)— (1)
Costs and expenses2 2 4 4 
Remeasurement of benefit obligation
(1)(1)1 (3)
Remeasurement of plan assets— — — — 
Remeasurement (gains) losses(1)(1)1 (3)
Postretirement net cost$1 $1 $5 $1 
Pension and postretirement benefits
Costs and expenses$9 $(23)$18 $(7)
Remeasurement (gains) losses— (9)78 (11)
Total net cost (benefit)$9 $(32)$96 $(18)
(1)    For the second quarter and first six months of 2024, service cost includes a $38 million refund of premiums previously paid to the Pension Benefit Guaranty Corporation.
Schedule of Pension and Postretirement Benefits Remeasurement Gains and Losses
Pension and postretirement benefits remeasurement gains and losses
Three months ended June 30,Six months ended June 30,
($ in millions)2025202420252024
Remeasurement of benefit obligation (gains) losses:
Discount rate$5 $(57)$64 $(98)
Other assumptions49 (12)45 2 
Remeasurement of plan assets (gains) losses(54)60 (31)85 
Remeasurement (gains) losses$— $(9)$78 $(11)