v3.25.2
Business Segment Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Segment Reporting Information [Line Items]            
Income Tax Expense (Benefit) $ 6,635   $ 12,610   $ 42,575 $ 16,519
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest 15,763   21,047   34,311 35,657
Net Income (Loss) Attributable to Parent 28,749 $ 101,143 41,794 $ 17,162    
Segment, Expenditure, Addition to Long-Lived Assets 149,708   278,746   296,824 537,870
UTILITY OPERATING REVENUES 438,684   397,594   916,384 805,395
Fuel Costs 99,973   77,639   206,482 180,558
Cost of Goods and Services Sold 31,239   44,103   66,769 82,736
Utilities Operating Expense, Maintenance and Operations 142,308   109,092   284,916 224,460
Depreciation and amortization 92,469   82,920   178,074 163,353
Taxes other than income taxes 4,231   6,547   13,303 14,442
Allowance for equity funds used during construction (732)   (1,269)   (1,401) (2,100)
Interest Expense 46,592   43,835   90,583 87,483
Segment Reporting, Other Segment Item, Amount 206   1,070   772 2,287
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest 22,398   33,657   76,886 52,176
Other Segments [Member]            
Segment Reporting Information [Line Items]            
Income Tax Expense (Benefit) (3,959)   (2,130)   (4,211) (3,908)
Net Income (Loss) Attributable to Parent (6,545)   (8,190)   (16,882) (16,865)
UTILITY OPERATING REVENUES 0   0      
Utilities Operating Expense, Maintenance and Operations 96   111   218 233
Interest Expense 10,447   10,950   20,895 22,221
Segment Reporting, Other Segment Item, Amount (39)   (741)   (20) (1,681)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest (10,504)   (10,320)   (21,093) (20,773)
Corporate Segment            
Segment Reporting Information [Line Items]            
Income Tax Expense (Benefit) 10,594   14,740   46,786 20,427
Net Income (Loss) Attributable to Parent 22,308   29,237   51,193 52,522
Segment, Expenditure, Addition to Long-Lived Assets 149,708   278,746   296,824 537,870
UTILITY OPERATING REVENUES 438,684   397,594   916,384 805,395
Fuel Costs 99,973   77,639   206,482 180,558
Cost of Goods and Services Sold 31,239   44,103   66,769 82,736
Utilities Operating Expense, Maintenance and Operations 142,212   108,981   284,698 224,227
Depreciation and amortization 92,469   82,920   178,074 163,353
Taxes other than income taxes 4,231   6,547   13,303 14,442
Allowance for equity funds used during construction (732)   (1,269)   (1,401) (2,100)
Interest Expense 36,145   32,885   69,688 65,262
Segment Reporting, Other Segment Item, Amount 245   1,811   792 3,968
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest 32,902   43,977   97,979 72,949
Electricity [Member]            
Segment Reporting Information [Line Items]            
UTILITY OPERATING REVENUES $ 438,684   $ 397,594   $ 916,384 $ 805,395