Segment Information - Financial Information About Reportable Segments and Corporate and Unallocated (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Revenue	$ 2,371,555	$ 2,330,197	$ 2,206,785
Home construction and land sales expenses	2,021,082	1,903,907	1,763,449
Inventory impairments and abandonments	12,959	1,996	641
Commissions	76,911	80,056	73,450
Sales and marketing	64,784	56,904	47,813
Other general and administrative expenses	140,046	129,441	131,981
Depreciation and amortization	19,168	14,867	12,198
Operating income	36,605	143,026	177,253
Loss on extinguishment of debt, net	0	(437)	(546)
Other income, net	4,245	16,496	5,939
Income from continuing operations before income taxes	40,850	159,085	182,646
Total assets	2,609,708	2,591,527	2,411,033
Gain on sale of investment		8,600
Operating Segments
Segment Reporting Information [Line Items]
Revenue	2,371,555	2,330,197	2,206,785
Home construction and land sales expenses	1,945,814	1,843,663	1,699,015
Inventory impairments and abandonments	10,719	1,996	641
Commissions	76,911	80,056	73,450
Sales and marketing	50,407	45,322	38,830
Other general and administrative expenses	61,228	57,767	55,785
Depreciation and amortization	14,124	13,090	10,867
Operating income	212,352	288,303	328,197
Total assets	1,973,059	1,957,763	1,671,047
Operating Segments | West
Segment Reporting Information [Line Items]
Revenue	1,476,311	1,467,287	1,297,005
Home construction and land sales expenses	1,206,374	1,154,678	986,289
Inventory impairments and abandonments	4,652	1,805	487
Commissions	48,940	50,658	43,971
Sales and marketing	30,703	27,560	23,378
Other general and administrative expenses	33,376	33,027	29,480
Depreciation and amortization	9,752	9,820	7,550
Operating income	142,514	189,739	205,850
Total assets	1,060,650	1,114,450	994,597
Operating Segments | East
Segment Reporting Information [Line Items]
Revenue	585,337	501,206	505,844
Home construction and land sales expenses	484,521	407,243	401,852
Inventory impairments and abandonments	215	91	154
Commissions	17,335	15,846	15,100
Sales and marketing	11,152	10,013	8,472
Other general and administrative expenses	14,968	13,323	13,583
Depreciation and amortization	2,491	1,792	1,662
Operating income	54,655	52,898	65,021
Total assets	451,299	454,255	356,020
Operating Segments | Southeast
Segment Reporting Information [Line Items]
Revenue	309,907	361,704	403,936
Home construction and land sales expenses	254,919	281,742	310,874
Inventory impairments and abandonments	5,852	100	0
Commissions	10,636	13,552	14,379
Sales and marketing	8,552	7,749	6,980
Other general and administrative expenses	12,884	11,417	12,722
Depreciation and amortization	1,881	1,478	1,655
Operating income	15,183	45,666	57,326
Total assets	461,110	389,058	320,430
Corporate and unallocated
Segment Reporting Information [Line Items]
Revenue	0	0	0
Home construction and land sales expenses	75,268	60,244	64,434
Inventory impairments and abandonments	2,240	0	0
Commissions	0	0	0
Sales and marketing	14,377	11,582	8,983
Other general and administrative expenses	78,818	71,674	76,196
Depreciation and amortization	5,044	1,777	1,331
Operating income	(175,747)	(145,277)	(150,944)
Total assets	$ 636,649	$ 633,764	$ 739,986