v3.26.1
Related-Party Transactions - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Related Party Transaction [Line Items]        
Total revenue $ 649,848 $ 602,533 $ 1,589,973 $ 1,220,939
Provision for receivables from related parties 0   0  
Related Party        
Related Party Transaction [Line Items]        
Total revenue 49,668 35,607 272,065 273,407
Consulting Services Revenue | Related Party        
Related Party Transaction [Line Items]        
Total revenue $ 100 $ 1,600 $ 200 $ 7,000
AES Grid Stability | Class B-1 common stock | Fluence Energy, Inc        
Related Party Transaction [Line Items]        
Investment owned (in shares) 41,432,781   41,432,781  
Siemens Industry | Class A common stock | Fluence Energy, Inc        
Related Party Transaction [Line Items]        
Investment owned (in shares) 41,432,781   41,432,781