Notes Payable - Forestar Textuals (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Letters of credit, amount outstanding	$ 254.3
Forestar Group [Member]
Debt Instrument [Line Items]
Line of credit, current borrowing capacity	410.0
Line of credit, maximum borrowing capacity	600.0
Letter of Credit, Maximum Borrowing Capacity (in dollars)	$ 100.0
Letter of Credit, Maximum Borrowing Capacity	50.00%
Line of credit, amount outstanding	$ 0.0	$ 0.0
Letters of credit, amount outstanding	27.7
Line of Credit Facility, Remaining Borrowing Capacity	382.3
Debt Instrument, Face Amount	700.0
Authorized Repurchase Of Debt Securities	30.0
Debt Repurchase Authorization Remaining	30.0
Forestar Group [Member] | Senior Note Member Forty Three
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 300.0
Senior notes, stated interest rate	5.00%
Debt Instrument, Interest Rate, Effective Percentage	5.20%
Forestar Group [Member] | Senior Note Forty Seven
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 400.0
Senior notes, stated interest rate	3.85%
Debt Instrument, Interest Rate, Effective Percentage	4.10%