Segment Information - Schedule of Financial Information About Reportable Segments and Corporate and Unallocated (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Sep. 30, 2025
Segment Reporting Information [Line Items]
Revenue	$ 363,491	$ 468,953
Home construction and land sales expenses	323,917	396,875
Inventory impairments and abandonments	2,370	0
Commissions	12,016	16,113
Sales and marketing	19,277	14,913
Other general and administrative expenses	33,712	34,859
Depreciation and amortization	4,042	4,055
Operating income (loss)	(31,843)	2,138
Other income, net	778	1,028
(Loss) income before income taxes	(31,065)	3,166
Total assets	2,639,713	2,600,528	$ 2,609,708
Operating Segments
Segment Reporting Information [Line Items]
Revenue	363,491	468,953
Home construction and land sales expenses	311,402	387,516
Inventory impairments and abandonments	2,248
Commissions	12,016	16,113
Sales and marketing	14,003	11,928
Other general and administrative expenses	13,427	13,744
Depreciation and amortization	2,669	2,945
Operating income (loss)	7,726	36,707
Total assets	2,049,576	2,086,087
Operating Segments | West
Segment Reporting Information [Line Items]
Revenue	223,504	298,916
Home construction and land sales expenses	192,178	243,909
Inventory impairments and abandonments	1,349
Commissions	7,723	10,562
Sales and marketing	8,714	7,246
Other general and administrative expenses	7,561	7,594
Depreciation and amortization	1,798	2,191
Operating income (loss)	4,181	27,414
Total assets	1,096,705	1,178,094
Operating Segments | East
Segment Reporting Information [Line Items]
Revenue	93,459	109,882
Home construction and land sales expenses	79,519	93,215
Inventory impairments and abandonments	899
Commissions	2,597	3,420
Sales and marketing	3,137	2,683
Other general and administrative expenses	3,299	3,436
Depreciation and amortization	475	456
Operating income (loss)	3,533	6,672
Total assets	451,228	485,806
Operating Segments | Southeast
Segment Reporting Information [Line Items]
Revenue	46,528	60,155
Home construction and land sales expenses	39,705	50,392
Inventory impairments and abandonments	0
Commissions	1,696	2,131
Sales and marketing	2,152	1,999
Other general and administrative expenses	2,567	2,714
Depreciation and amortization	396	298
Operating income (loss)	12	2,621
Total assets	501,643	422,187
Corporate and unallocated
Segment Reporting Information [Line Items]
Revenue	0	0
Home construction and land sales expenses	12,515	9,359
Inventory impairments and abandonments	122
Commissions	0	0
Sales and marketing	5,274	2,985
Other general and administrative expenses	20,285	21,115
Depreciation and amortization	1,373	1,110
Operating income (loss)	(39,569)	(34,569)
Total assets	$ 590,137	$ 514,441