Income Taxes - Additional Information (Detail) $ in Thousands, BitCoinUnits in Millions			3 Months Ended			6 Months Ended
	May 30, 2025 USD ($)	Apr. 24, 2024 USD ($) BitCoinUnits	Sep. 30, 2025	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)
Income tax (expense)				$ (1,162)	$ (270)	$ (2,614)	$ (132)
Uncertain tax position				1,000		1,000
Forecast [Member]
Change in annual effective tax rate			3.94%
BT Hold Co LLC [Member]
Income tax (expense)						$ (2,600)	$ (100)
Effective income tax rate reconciliation, percent						(9.65%)	51.97%
Net income (loss) before tax attributable to non controlling interest						$ (200)	$ 300
Tax Receivable Agreement [Member]
Tax receivable agreement liability								$ 900	$ 700
Tax receivable agreement liability additional adjustment		$ 1,300						$ 200
Percentage of aggregate tax benefits		85.00%
Tax Receivable Agreement [Member] | BT Hold Co LLC [Member]
Tax savings percentage distributable						85.00%
Payable as per tax receivable agreement				$ 2,200		$ 2,200
Aggregate number of units in connection with exchange | BitCoinUnits		2.9
Tax Receivable Agreement [Member] | BT Assets [Member]
Cash payments for termination of agreement	$ 8,400