Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2025 USD ($) region state	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) segment region state	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)
Segment Reporting Information [Line Items]
Number of states in which home building segments operate | state	13		13
Number of regions in which entity operates | region	3		3
Number of reportable segments | segment			3
Revenue	$ 545,367	$ 595,682	$ 1,579,659	$ 1,524,040
Operating (loss) income	(3,710)	28,524	11,797	84,780
Depreciation and amortization	4,571	3,892	13,273	9,698
Capital expenditures			21,027	16,691
Assets	2,712,324		2,712,324		$ 2,591,527
Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	39,314	67,495	126,790	180,595
Depreciation and amortization	3,212	3,411	9,620	8,377
Corporate and unallocated
Segment Reporting Information [Line Items]
Operating (loss) income	(43,024)	(38,971)	(114,993)	(95,815)
Depreciation and amortization	1,359	481	3,653	1,321
Capital expenditures			7,373	4,974
Assets	503,479		503,479		633,764
West
Segment Reporting Information [Line Items]
Revenue	329,149	369,359	1,001,921	953,790
West | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	27,402	45,582	94,291	119,951
Depreciation and amortization	2,151	2,520	6,860	6,283
Capital expenditures			7,627	9,132
Assets	1,222,047		1,222,047		1,114,450
East
Segment Reporting Information [Line Items]
Revenue	149,160	123,565	379,898	310,186
East | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	14,473	9,158	28,702	27,796
Depreciation and amortization	633	494	1,637	1,109
Capital expenditures			2,274	1,829
Assets	512,577		512,577		454,255
Southeast
Segment Reporting Information [Line Items]
Revenue	67,058	102,758	197,840	260,064
Southeast | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	(2,561)	12,755	3,797	32,848
Depreciation and amortization	428	$ 397	1,123	985
Capital expenditures			3,753	$ 756
Assets	$ 474,221		$ 474,221		$ 389,058