XML 65 R53.htm IDEA: XBRL DOCUMENT v3.21.1
Employee Benefit Plans (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Defined Benefit Pension Plans    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost $ 1,259 $ 1,353
Interest cost 2,328 3,357
Expected return on plan assets (5,219) (5,648)
Net loss (gain) 1,829 2,093
Net periodic benefit cost 197 1,155
Payment for Pension and Other Postretirement Benefits [Abstract]    
Contributions by Employer 0  
Estimated Future Employer Contributions in Current Fiscal Year 0  
Estimated Future Employer Contributions in Next Fiscal Year 3,788  
Other Postretirement Benefits Plan    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 559 514
Interest cost 265 412
Expected return on plan assets (34) (45)
Prior service cost (benefit) (109) (137)
Net loss (gain) 117 5
Net periodic benefit cost 798 749
Payment for Pension and Other Postretirement Benefits [Abstract]    
Contributions by Employer 1,382  
Estimated Future Employer Contributions in Current Fiscal Year 4,145  
Estimated Future Employer Contributions in Next Fiscal Year 5,241  
Supplemental Non-qualified Defined Benefit and Defined Contribution Plans    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 693 1,370
Interest cost 177 275
Net loss (gain) 439 426
Net periodic benefit cost 1,309 $ (669)
Payment for Pension and Other Postretirement Benefits [Abstract]    
Contributions by Employer 482  
Estimated Future Employer Contributions in Current Fiscal Year 1,445  
Estimated Future Employer Contributions in Next Fiscal Year $ 1,967