Mortgage Servicing Rights and Related Liabilities - Servicing Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Transfers and Servicing [Abstract]
Contractually specified servicing fees(1)	$ 514,000,000	$ 384,000,000
Other service-related income(1)	22,000,000	14,000,000
Incentive and modification income(1)	18,000,000	6,000,000
Servicing late fees(1)	30,000,000	21,000,000
MSR MTM	(189,000,000)	105,000,000
Loss (gain) on MSR hedging activities	(122,000,000)	59,000,000
Loss on MSR sales	(12,000,000)	0
Reclassifications(2)	(6,000,000)	(9,000,000)
Excess spread / MSR financing MTM	(6,000,000)	(6,000,000)
Total mark-to-market adjustments - Servicing	(43,000,000)	61,000,000
MSR amortization	179,000,000	125,000,000
Excess spread accretion	(9,000,000)	(10,000,000)
Total amortization, net of accretion	170,000,000	115,000,000
Originations service fees(3)	16,000,000	11,000,000
Corporate/Xome related service fees	22,000,000	19,000,000
Other(4)	17,000,000	18,000,000
Total revenues - Service Related, net	478,000,000	261,000,000
Cash Flows Between Transferor and Transferee, Servicing Fees	$ 185,000,000	$ 177,000,000