Owned Inventory - Impairment Charges Taken on Projects in Progress (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2025 USD ($) community lot	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Segment Reporting Information [Line Items]
# of Communities Impaired | community	2
# of Lots Impaired | lot	89
Impairment Charge	$ 8,642	$ 0	$ 0
Level 3 | Fair Value, Measurements, Nonrecurring
Segment Reporting Information [Line Items]
Estimated Fair Value of Impaired Inventory at Time of Impairment	$ 19,050
Operating Segments | West
Segment Reporting Information [Line Items]
# of Communities Impaired | community	1
# of Lots Impaired | lot	24
Impairment Charge	$ 2,236	0	0
Operating Segments | West | Level 3 | Fair Value, Measurements, Nonrecurring
Segment Reporting Information [Line Items]
Estimated Fair Value of Impaired Inventory at Time of Impairment	$ 5,003
Operating Segments | Southeast
Segment Reporting Information [Line Items]
# of Communities Impaired | community	1
# of Lots Impaired | lot	65
Impairment Charge	$ 5,404	0	0
Operating Segments | Southeast | Level 3 | Fair Value, Measurements, Nonrecurring
Segment Reporting Information [Line Items]
Estimated Fair Value of Impaired Inventory at Time of Impairment	$ 11,837
Corporate and unallocated
Segment Reporting Information [Line Items]
# of Communities Impaired | community	0
# of Lots Impaired | lot	0
Impairment Charge	$ 1,002	$ 0	$ 0
Corporate and unallocated | Level 3 | Fair Value, Measurements, Nonrecurring
Segment Reporting Information [Line Items]
Estimated Fair Value of Impaired Inventory at Time of Impairment	$ 2,210