v3.26.1
Revenue Recognition - Schedule of Sales to Members and Sales to Non-Members (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Revenue Recognition        
Total operating revenues $ 589,470 $ 633,748 $ 1,326,526 $ 1,311,324
Sales to members        
Revenue Recognition        
Total operating revenues 574,157 601,690 1,281,158 1,269,991
Sales to members | Capacity revenues        
Revenue Recognition        
Total operating revenues 395,398 422,959 817,639 836,296
Sales to members | Energy revenues        
Revenue Recognition        
Total operating revenues 178,759 178,731 463,519 433,695
Sales to non-members        
Revenue Recognition        
Total operating revenues 15,313 32,058 45,368 41,333
Sales to non-members | Energy revenues        
Revenue Recognition        
Total operating revenues $ 15,313 $ 32,058 $ 45,368 $ 41,333