Advances and Other Receivables - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Receivables [Abstract]
Servicing advances, net of $12 purchase discount	$ 813		$ 1,053
Receivables from agencies, investors and prior servicers, net of $7 purchase discount	109		103
Reserves	(164)		(137)
Total advances and other receivables, net	758		1,019
Servicing advances discount	12	$ 9	12	$ 12	$ 14	$ 19
Receivables discount	$ 7	$ 7	$ 7	$ 7	$ 8	$ 12