Mortgage Loans Held for Sale - Mortgage Loans Held for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale – UPB	$ 932	$ 921
Mark-to-market adjustment(1)	(39)	(28)
Total mortgage loans held for sale	893	893
UPB	41	102
Fair Value	32	87
Ginnie mae repurchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
UPB	$ 32	$ 90

Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481990/310-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481852/948-310-45-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant