XML 118 R97.htm IDEA: XBRL DOCUMENT v3.22.4
Employee Benefit Plans: Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($)
$ in Thousands
Dec. 31, 2022
Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]    
Regulatory assets $ 652,981 $ 796,599
Benefit plan liabilities 116,742 123,925
Regulatory liabilities 518,573 502,951
Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Regulatory assets 78,654 67,403
Current liabilities 0 0
Non-current assets 0 0
Benefit plan liabilities 35,243 19,872
Regulatory liabilities 2,804 3,830
Supplemental Employee Retirement Plan    
Defined Benefit Plan Disclosure [Line Items]    
Regulatory assets 0 0
Current liabilities 2,231 2,156
Non-current assets 0 0
Benefit plan liabilities 42,994 53,104
Regulatory liabilities  
Other Postretirement Benefits Plan    
Defined Benefit Plan Disclosure [Line Items]    
Regulatory assets 3,788 11,660
Current liabilities 4,427 4,584
Non-current assets 959 0
Benefit plan liabilities 38,505 50,949
Regulatory liabilities $ 6,198 $ 2,447