Revenue (Details) $ in Millions	12 Months Ended
	Sep. 30, 2022 USD ($) Lot	Sep. 30, 2021 USD ($) Lot	Sep. 30, 2020 USD ($) Lot
Revenue from External Customer [Line Items]
Deferred development lot sales	$ 26.8	$ 0.0	$ 0.0
Tract sales and other	36.8	32.7	51.5
Revenues	1,519.1	$ 1,325.8	$ 931.8
Number of Lots Sold | Lot		15,915	10,373
Deferred Development Project
Revenue from External Customer [Line Items]
Residential lot sales	$ 64.1
Number of Lots Sold | Lot	854
Proceeds from Deposits from Customers	$ 38.8
D.R. Horton, Inc. [Member]
Revenue from External Customer [Line Items]
Revenues	1,200.0	$ 1,200.0	$ 887.6
Real Estate | Residential Real Estate [Member]
Revenue from External Customer [Line Items]
Residential lot sales	$ 1,455.5	$ 1,293.1	$ 880.3