Mortgage Servicing Rights - Effect of Hypothetical Changes in the Fair Value of MSRs (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Transfers and Servicing [Abstract]
Loans serviced	$ 1,127	$ 1,124	$ 1,148
Adverse change	(64)
Favorable change	49
Increase	(25)
Decrease	26
Increase	(30)
Decrease	33
Increase	(13)
Decrease	$ 13

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
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-Section 45
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481260/860-50-45-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
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-URI https://asc.fasb.org/1943274/2147481260/860-50-45-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Decrease Cost of Service

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Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 50 basis point Adverse Interest Rate Change

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Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 50 basis point Favorable Interest Rate Change

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