Other Assets, Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Other assets
Earnest money and refundable deposits	$ 1,859.6	$ 1,685.7
Mortgage hedging instruments and commitments	153.6	330.2
Water rights and other water-related assets	319.6	286.6
Other receivables	167.2	210.9
Insurance receivables	165.8	137.9
Prepaid assets	93.0	77.4
Contract assets - insurance agency commissions	93.9	74.3
Lease right of use assets	46.6	46.6
Mortgage servicing rights	11.1	10.6
Other	$ 80.3	$ 52.4
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets
Total other assets	$ 2,993.0	$ 2,960.3
Accrued expenses and other liabilities
Reserves for legal claims	858.9	729.1	$ 577.5
Employee compensation and related liabilities	531.0	524.3
Warranty liability	512.4	454.3	$ 376.3
Inventory related accruals	353.6	403.6
Broker deposits related to hedging instruments	118.9	240.9
Customer deposits	147.1	224.2
Federal and state income tax liabilities	233.8	110.9
Accrued property taxes	69.2	60.1
Lease liabilities	48.1	47.9
Accrued interest	33.6	33.8
Mortgage hedging instruments and commitments	15.7	12.4
Other	$ 147.6	$ 113.3
Finance Lease, Right-of-Use Asset, Accumulated Amortization	Other Liabilities	Other Liabilities
Total accrued expenses and other liabilities	$ 3,103.8	$ 3,138.3
Interest Rate Lock Commitments
Other assets
Interest rate lock commitments	2.3	47.7
Accrued expenses and other liabilities
Interest rate lock commitments	$ 33.9	$ 183.5