Inventory - Narrative (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2025 USD ($) community home	Dec. 31, 2024 USD ($)	Sep. 30, 2025 USD ($) home
Inventory Disclosure [Abstract]
Number of homes under construction | home	1,868		1,800
Number of homes under construction, spec homes | home	1,091		1,078
Total, spec homes	$ 411,800		$ 417,400
Number of homes under construction, in-process spec homes | home	569		577
In-process spec homes	$ 181,900		$ 201,800
Number of homes under construction, finished spec homes | home	522		501
Finished spec homes	$ 229,900		$ 215,600
Threshold number of homes below a minimum threshold of profitability | home	10
Total impairment charges on projects in progress	$ 0	$ 0
Total impairment charges on land held for sale	$ 1,045	0
Number of impaired land held for sale communities (in community) | community	2
Estimated fair value less cost to sell of land held for sale assets at time of impairment	$ 14,000
Abandonments charges	$ 1,325	$ 0