v3.25.1
Debt - Department of Energy Loan Guarantee (Details) - USD ($)
3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Feb. 20, 2014
Debt      
Repayments of long-term debt $ 133,149,000 $ 136,047,000  
Long-term debt | Department of Energy guarantee      
Debt      
Aggregate borrowings including capitalized interest 4,017,956,000    
Long-term debt | FFB      
Debt      
Maximum borrowing capacity designated for capitalized interest     $ 4,633,028,000
Repayments of long-term debt $ 615,072,000