v3.26.1
General - Consolidated Balance Sheets (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
ASSETS            
Non-trade receivables $ 65.1   $ 38.1 $ 17.1    
Total current assets 1,401.6   1,031.3 807.4    
Property, plant and equipment - net 1,253.0   1,167.6 1,150.8    
Other assets 172.1   70.4 70.6    
TOTAL 2,875.1   2,269.3 2,142.3    
LIABILITIES            
Accrued compensation and benefits 77.1   74.4 45.2    
Non-trade payables       0.0    
Accrued and other current liabilities 43.6   35.6 48.0    
Total current liabilities 509.4   523.6 447.5    
Accrued benefits costs - less current portion 92.1   97.7 142.3    
Asset retirement obligations - less current portion 74.3   75.3 82.5    
Total noncurrent liabilities 831.2   815.8 847.4    
SHAREHOLDERS’ EQUITY:            
Noncontrolling interests 131.4   124.3 123.0    
Total equity 1,534.5 $ 1,284.5 929.9 847.4 $ 837.8 $ 805.3
TOTAL $ 2,875.1   $ 2,269.3 2,142.3    
As Previously Reported            
ASSETS            
Non-trade receivables       0.0    
Total current assets       790.3    
Property, plant and equipment - net       975.6    
Other assets       69.6    
TOTAL       1,949.0    
LIABILITIES            
Accrued compensation and benefits       44.2    
Non-trade payables       7.7    
Accrued and other current liabilities       44.9    
Total current liabilities       451.1    
Accrued benefits costs - less current portion       127.8    
Asset retirement obligations - less current portion       63.2    
Total noncurrent liabilities       813.6    
SHAREHOLDERS’ EQUITY:            
Noncontrolling interests       (40.1)    
Total equity       684.3 $ 690.7  
TOTAL       1,949.0    
Restatement Impacts            
ASSETS            
Non-trade receivables       17.1    
Total current assets       17.1    
Property, plant and equipment - net       175.2    
Other assets       1.0    
TOTAL       193.3    
LIABILITIES            
Accrued compensation and benefits       1.0    
Non-trade payables       (7.7)    
Accrued and other current liabilities       3.1    
Total current liabilities       (3.6)    
Accrued benefits costs - less current portion       14.5    
Asset retirement obligations - less current portion       19.3    
Total noncurrent liabilities       33.8    
SHAREHOLDERS’ EQUITY:            
Noncontrolling interests       163.1    
Total equity       163.1    
TOTAL       $ 193.3