Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from External Customer [Line Items]
Deferred development lot sales	$ 1.3	$ 6.7
Tract sales and other	0.4	3.3
Revenues	305.9	216.7
Real Estate | Residential Real Estate [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 304.2	$ 206.7