Notes Payable - Forestar Textuals (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2025	Jun. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		$ 281.5
Forestar Group [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity		640.0	$ 410.0
Line of Credit Facility, Maximum Borrowing Capacity		1,000.0
Letter of Credit, Maximum Borrowing Capacity (in dollars)		$ 100.0
Letters of credit, sublimit borrowing capacity, as a percentage		50.00%
Borrowings outstanding on revolving credit facility		$ 0.0	$ 0.0
Letters of Credit Outstanding, Amount		37.2
Line of Credit Facility, Remaining Borrowing Capacity		602.8
Authorized Repurchase Of Debt Securities		30.0
Debt Repurchase Authorization Remaining		$ 30.0
Forestar Group [Member] | 6.5% Senior Note de 2033
Debt Instrument [Line Items]
Debt Instrument, Issued, Principal	$ 500.0
Debt Instrument, Interest Rate, Stated Percentage		6.50%
Debt Instrument, Interest Rate, Effective Percentage		6.70%
Forestar Group [Member] | Senior Note Member Forty Six
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.85%
Debt Instrument, Redemption Price	333.4
Debt Instrument, Redemption, Accrued and Unpaid Interest	4.2
Debt Instrument, Repurchased Face Amount	400.0
Debt Instrument, Repurchase Amount	329.4
Gain (Loss) on Repurchase of Debt Instrument	$ 1.1
Forestar Group [Member] | Credit Facility Maturing December 18, 2029
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity		$ 575.0
Line of Credit Facility, Expiration Date		Dec. 18, 2029
Forestar Group [Member] | Credit Facility Maturing October 28, 2026
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity		$ 65.0
Line of Credit Facility, Expiration Date		Oct. 28, 2026