v3.25.2
Postretirement Benefit Obligations
 6 Months Ended
Jun. 30, 2025
Postemployment Benefits [Abstract]  
Postretirement Benefit Obligations
12. Postretirement Benefit Obligations
TES and certain subsidiaries sponsor postemployment benefits which include defined benefit pension plans, health and welfare postretirement plans (other postretirement benefit plans), and a defined contribution plan.
The components of net periodic benefit costs for the periods were:
 Three Months Ended June 30,Six Months Ended June 30,
2025202420252024
Postretirement benefits service cost (a)
$— $1 $1 $2 
Postretirement benefit (gain) loss
Interest cost$17 $17 34 33 
Expected return on plan assets(18)(17)(37)(35)
Amortization of:
Postretirement prior service cost (credit)(1)— (2)— 
Postretirement benefit (gain) loss, net (b)
$(2)$— (5)(2)
Net periodic defined benefit cost (credit)$(2)$1 $(4)$— 
_____________
(a)Activity presented as “Operation, maintenance and development” on the Consolidated Statements of Operations.
(b)Activity presented as “Other non-operating income (expense), net” on the Consolidated Statements of Operations.