Advances and Other Receivables - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Receivables [Abstract]
Servicing advances, net of $12 and $13 purchase discount	$ 998	$ 1,065
Receivables from agencies, investors and prior servicers, net of zero and $6 purchase discount	60	101
Reserves	(144)	(170)
Total advances and other receivables, net	914	996
Servicing advances discount	12	13	$ 9	$ 12
Receivables discount	$ 0	$ 6	$ 7	$ 7