Advances and Other Receivables - Purchase Discount (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Servicing Advances
Servicing Advances, Discount	$ 14	$ 31	$ 19	$ 72
Accretion of Service Advances Discount	(2)	(1)	(7)	(42)
Servicing Advances, Discount	12	30	12	30
Receivables from Agencies, Investors and Prior Servicers
Receivable with Imputed Interest, Discount	7	13	7	13
Receivable Discount, Accretion Expense	(1)	(7)	(5)	(8)
Receivable with Imputed Interest, Discount	$ 8	$ 20	$ 12	$ 21