Income Taxes - Text (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		$ 2,300,000
Net operating loss carryforwards	$ 1,200,000	1,400,000
Deferred Tax Assets, Valuation Allowance	(1,000,000.0)	(1,200,000)
Unrecognized Tax Benefits	0	0	$ 0	$ 1,600,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense	0	0	0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,200,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	700,000
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	500,000
D.R. Horton, Inc. [Member] | Reimbursement To Parent [Member]
Operating Loss Carryforwards [Line Items]
Related Party Transaction, Amounts of Transaction	$ 700,000	$ 500,000	$ 200,000