Basis of Presentation and Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Total revenue	$ 468,953	$ 386,818
Customer deposits	20,845		$ 18,669
Contract with customer, liability, revenue recognized	8,200
Homebuilding revenue
Disaggregation of Revenue [Line Items]
Total revenue	460,422	380,919
Land sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 8,531	$ 5,899