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Financial assets - Schedule of Effect of Financial Instruments in Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Unrealized gain (loss) on financial asset		$ 664,993	$ 0
Realized gain (loss) on financial instruments		(5,756)	(4,215)
2030 Prepaid Forward Contract
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Unrealized gain (loss) on financial asset		184,483	0
2029 Prepaid Forward Contract
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Unrealized gain (loss) on financial asset		285,300	0
Electricity financial asset
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Unrealized gain (loss) on financial asset			(3,448)
Realized gain (loss) on financial instruments	$ (452)	0	(4,215)
Total financial assets		0
Prepaid forward and electricity contracts
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total financial assets		$ 469,783	$ (4,215)