XML 42 R30.htm IDEA: XBRL DOCUMENT v3.25.1
Retirement Benefits (Tables)
 3 Months Ended
Mar. 31, 2025
Retirement Benefits [Abstract]  
Components of Net Periodic Benefit Cost (Credit)
The components of the net periodic pension benefit cost for the three months ended March 31 were as follows:
20252024
 (Dollars in thousands)
Service cost$1,944 $2,165 
Interest cost8,119 8,413 
Expected return on plan assets(10,257)(10,771)
Amortization of prior service cost 8 23 
Amortization of actuarial losses1,893 1,852 
Net periodic benefit cost $1,707 $1,682 
 
The components of the net periodic other postretirement benefit cost for the three months ended March 31 were as follows:
20252024
(Dollars in thousands)
Service cost$4 $7 
Interest cost151 165 
Amortization of prior service credit(15)(5)
Amortization of actuarial gains(86)(84)
Net periodic benefit cost $54 $83