Advances and Other Receivables, Net - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Receivables [Abstract]
Servicing advances, net of $92 and $131 purchase discount, respectively	$ 746		$ 970
Receivables from agencies, investors and prior servicers, net of $21 and $21 purchase discount, respectively	190		193
Reserves	(191)		(175)
Total advances and other receivables, net	745		988
Servicing advances discount	92	$ 117	131	$ 148	$ 156	$ 205
Receivables discount	$ 21	$ 21	$ 21	$ 48	$ 48	$ 48