Advances and Other Receivables - Purchase Discount (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Servicing Advances
Balance - beginning of year	$ 12	$ 19
Addition from acquisition(1)	5	0
Utilization of purchase discounts	(4)	(7)
Balance - end of year	13	12
Receivables from Agencies, Investors and Prior Servicers
Balance - beginning of year	7	12
Addition from acquisition(1)	0	0
Utilization of purchase discounts	(1)	(5)
Balance - end of year	6	7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Addition from acquisition(1)	5	$ 0
Home Point Capital Inc
Servicing Advances
Addition from acquisition(1)	5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Addition from acquisition(1)	$ 5