Advances and Other Receivables - Purchase Discount (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Servicing Advances
Balance - beginning of period	$ 72	$ 131
Utilization of purchase discounts	(9)	(6)
Balance - end of period	63	125
Receivables from Agencies, Investors and Prior Servicers
Balance - beginning of period	20	21
Utilization of purchase discounts	(1)	0
Balance - end of period	$ 21	$ 21

Disclosure of the unamortized amount of the discount on the note or receivable which is deducted from the face amount of the receivable or loan. The discount or premium is the difference between the present value and the face amount.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Name:	us-gaap_ReceivableWithImputedInterestDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant