XML 75 R59.htm IDEA: XBRL DOCUMENT v3.22.0.1
Employee Benefit Plans, Components of Net Periodic Benefit Cost (Details) - Defined Benefit Pension Plans Combined [Member] - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Components of Net Periodic Pension Cost [Abstract]    
Service cost $ 1,086 $ 938
Interest cost 1,209 1,457
Expected return on plan assets (3,651) (3,198)
Amortization of loss 483 370
Amortization of prior service cost (13) (13)
Rate-regulated adjustment 3,186 2,746
Net periodic benefit cost 2,300 $ 2,300
Change in defined benefit plan regulatory asset from pension contribution greater (less) than net periodic benefit cost 3,186  
Amortization of Regulatory Assets to be Reclassified into Net Periodic Benefit Cost [Abstract]    
Net loss 0  
Net prior service credit (13)  
Total amortization of regulatory assets to be reclassified into net periodic benefit cost during the next fiscal year $ (13)