Advances and Other Receivables - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Receivables [Abstract]
Servicing advances, net of $7 and $13 purchase discount	$ 1,012		$ 1,065
Receivables from agencies, investors and prior servicers, net of zero and $6 purchase discount	43		101
Reserves	(115)		(170)
Total advances and other receivables, net	940		996
Servicing advances discount	7	$ 12	13	$ 12	$ 9	$ 12
Receivables discount	$ 0	$ 0	$ 6	$ 7	$ 7	$ 7