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Summary of Significant Accounting Policies and Estimates - Schedule of Non-controlling Interest (Details)	Jun. 30, 2026	May 15, 2026	Sep. 30, 2025
Fluence Energy, LLC
Noncontrolling Interest [Line Items]
Controlling Interest Ownership	77.55%	77.54%	71.81%
AES Grid Stability
Noncontrolling Interest [Line Items]
Non-Controlling Interest Ownership (AES)	22.45%		28.19%