Mortgage Servicing Rights - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Transfers and Servicing [Abstract]
Residential mortgage loans serviced for others including subserviced mortgages with no corresponding MSRs asset	$ 216,700		$ 216,600
Gain (loss) on fair value changes of MSRs due to changes in valuation assumptions and derivatives used to economically hedge MSRs	2	$ (3)
Loan servicing and ancillary fees	$ 172	$ 180

Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

Name:	us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration