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Debt - Narrative (Details) - USD ($)	3 Months Ended			6 Months Ended
Debt - Narrative (Details) - USD ($)	Jun. 30, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024	Jun. 09, 2025	Apr. 29, 2025	Apr. 28, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 0	$ 1,000,000		$ 0	$ 1,000,000
2025 Notes \| Convertible Debt
Debt Instrument [Line Items]
Debt instrument, repurchased face amount		88,000,000			$ 88,000,000
Cash paid for repurchase		$ 89,000,000
Loss on extinguishment of debt			$ 1,000,000
Repayment of principal amount				419,000,000
Payments for debt				425,000,000
Payments for debt, accrued interest				6,000,000
Mortgages Segment
Debt Instrument [Line Items]
Total master repurchase agreements	230,000,000			230,000,000					$ 145,000,000
Line of Credit
Debt Instrument [Line Items]
Total maximum borrowing	600,000,000			600,000,000
Total master repurchase agreements	230,000,000			230,000,000
JPMorgan Chase Bank, N.A. \| Line of Credit
Debt Instrument [Line Items]
Total maximum borrowing	200,000,000			200,000,000			$ 200,000,000	$ 150,000,000
Total master repurchase agreements	92,000,000			92,000,000
JPMorgan Chase Bank, N.A. \| Line of Credit \| Mortgages Segment
Debt Instrument [Line Items]
Total master repurchase agreements	92,000,000			92,000,000					72,000,000
Bank of Nova Scotia \| Line of Credit
Debt Instrument [Line Items]
Total maximum borrowing	100,000,000			100,000,000		$ 100,000,000
Total master repurchase agreements	0			0
Atlas Securitized Products, L.P., JPMorgan Chase Bank, N.A, Citibank, N.A. \| Mortgages Segment
Debt Instrument [Line Items]
Total master repurchase agreements	$ 242,000,000			$ 242,000,000					$ 151,000,000