Mortgage Loans Held for Sale - Mortgage Loans Held for Sale (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale – UPB	$ 1,071	$ 924
Mark-to-market adjustment(1)	(1)	3
Total mortgage loans held for sale	1,070	927
UPB	38	42
Fair Value	31	36
Ginnie mae repurchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
UPB	$ 31	$ 35

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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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant