Other Assets, Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Schedule of Other Assets, Accrued Expenses and Other Liabilities [Line Items]
Earnest money notes receivable on sales contracts	$ 0.0	$ 0.7
Receivables, net	14.9	0.4
Lease right of use assets	7.8	6.9
Prepaid expenses	25.5	15.4
Land purchase contract deposits	11.2	10.4
Other assets	1.9	5.3
Total Other assets	61.3	39.1
Accrued employee compensation and benefits	8.3	7.9
Accrued property taxes	4.8	3.4
Lease liabilities	8.4	7.3
Accrued interest	7.8	8.5
Contract with Customer, Liability, Current	17.0	5.8
Deferred income	4.1	6.8
Income taxes payable	12.5	6.8
Other accrued expenses	3.6	8.9
Other liabilities	1.0	1.3
Total Accrued expenses and other liabilities	67.5	$ 56.7
Deferred Development Project
Schedule of Other Assets, Accrued Expenses and Other Liabilities [Line Items]
Contract with Customer, Liability, Current	$ 13.2