Other Assets, Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021
Other Assets, Accrued Expenses and Other Liabilities [Abstract]
Earnest money notes receivable on sales contracts	$ 0.6	$ 0.7
Other receivables	2.1	0.4
Lease right of use assets	7.2	6.9
Prepaid expenses	12.5	15.4
Land purchase contract deposits	10.8	10.4
Other assets	2.0	5.3
Total Other assets	35.2	39.1
Accrued employee compensation and benefits	5.3	7.9
Accrued property taxes	0.6	3.4
Lease liabilities	7.7	7.3
Accrued interest	7.5	8.5
Contract liabilities	3.7	5.8
Deferred income	6.8	6.8
Income taxes payable	19.9	6.8
Other accrued expenses	10.2	8.9
Other liabilities	1.2	1.3
Total Accrued expenses and other liabilities	$ 62.9	$ 56.7
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities