Income Taxes - Textual (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Apr. 30, 2022
Operating Loss Carryforwards [Line Items]
Effective tax rate	22.70%	21.80%	20.20%
Federal statutory rate	21.00%	21.00%	21.00%
Net operating loss carryforwards	$ 44.1	$ 11.7
Deferred Tax Assets, Valuation Allowance	17.9	$ 4.2
Vidler Water Resources, Inc.
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	30.9
Business acquisition, deferred income tax valuation allowance acquired				$ 15.8
Home Building | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	12.0
Home Building | State [Member] | NOL Carryforwards to Expire in One to Ten Years [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, subject to expiration	4.3
Home Building | State [Member] | NOL Carryforward to Expire in Eleven to Twenty Years [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, subject to expiration	7.7
Forestar Group [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1.2