Commitments and Contingencies (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Funded loans unpaid principal	$ 43,800.0	$ 43,800.0
Letters of credit outstanding	269.0	269.0
Accrued loan loss	61.0	61.0	$ 67.0
Assets available for recourse	2,400.0	2,400.0
Guarantees total	236.0	236.0
Recognized revenue included in contract liability	16.0	206.0
Contingent deferred consideration		(285.0)	(266.0)
Reserves for sales and use taxes	25.0	25.0	3.0
Commitments to investment in future real estate investment	154.0	$ 154.0
Commitments to investment in future real estate investment		0.50
Commitment to investment in consolidated projects	153.0	$ 153.0
Commitments to investment in unconsolidated real estate subsidiary	51.0	51.0
Accounts Payable, Accrued Expenses and Long-term Deferred and Contingent Consideration
Loss Contingencies [Line Items]
Recognized revenue included in contract liability		(283.0)	(264.0)
Performance Guarantee
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss	788.0	788.0	242.0
Warehouse Receivable
Loss Contingencies [Line Items]
Warehouse receivables	786.0	786.0
Funded Loan Subject to Loss Sharing Arrangements
Loss Contingencies [Line Items]
Funded loans unpaid principal	40,400.0	40,400.0
Letters of credit outstanding	160.0	160.0	140.0
SBL Program
Loss Contingencies [Line Items]
Letters of credit outstanding	$ 5.0	$ 5.0	$ 5.0
Percentage of maximum original principal amount loan loss	10.00%	10.00%
Funded Loan Not Subject to Loss Sharing Arrangements
Loss Contingencies [Line Items]
Letters of credit outstanding	$ 165.0	$ 165.0

Assets available for recourse under the Fannie Mae DUS lender program.

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