Advances and Other Receivables - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Servicing advances, net of $19 and $72 purchase discount, respectively	$ 1,263	$ 975
Receivables from agencies, investors and prior servicers, net of $12 and $21 purchase discount, respectively	132	173
Reserves	(167)	(208)
Total advances and other receivables, net	1,228	940
Servicing advances discount	19	72	$ 131
Receivable discount	$ 12	$ 21	$ 21