Advances and Other Receivables - Purchase Discount (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Mar. 31, 2024	Mar. 31, 2023
Servicing Advances
Servicing Advances, Discount	$ 13	$ 12
Utilization of purchase discounts	(1)	(3)
Servicing Advances, Discount	12	9
Receivables from Agencies, Investors and Prior Servicers
Receivable with Imputed Interest, Discount	0	7
Utilization of Purchase Discount	(6)	0
Receivable with Imputed Interest, Discount	6	7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Servicing advances discount	12	9	$ 12	$ 9
Receivables discount	0	7	$ 0	$ 7
Accretion of Service Advances Discount	1	3
Receivable Discount, Accretion Expense	$ 6	$ 0