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Mortgage Servicing - Summary of Delinquency Status of Loans Underlying Mortgage Servicing Rights (Details) - USD ($) $ in Billions | Sep. 30, 2025 | Dec. 31, 2024
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Participating Mortgage Loans [Line Items] |  |
Assets serviced | $ 189.8 | $ 170.3
Percent of aggregate unpaid principal balance | 5.40% | 6.50%
Financial Asset, 30 to 59 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 2.80% | 3.10%
Financial Asset, 60 to 89 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 0.90% | 1.10%
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 1.70% | 2.30%
Fair Value Non-Agency Mortgage Servicing Rights |  |
Participating Mortgage Loans [Line Items] |  |
Assets serviced | $ 20.0 | $ 21.6
Percent of aggregate unpaid principal balance | 17.30% | 18.70%
Fair Value Non-Agency Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 8.50% | 8.40%
Fair Value Non-Agency Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 2.90% | 3.40%
Fair Value Non-Agency Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 5.90% | 6.90%
Fair Value GSE Mortgage Servicing Rights |  |
Participating Mortgage Loans [Line Items] |  |
Assets serviced | $ 145.0 | $ 129.3
Percent of aggregate unpaid principal balance | 1.50% | 1.80%
Fair Value GSE Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 0.90% | 1.00%
Fair Value GSE Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 0.20% | 0.20%
Fair Value GSE Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 0.40% | 0.50%
Fair Value GNMA Mortgage Servicing Rights |  |
Participating Mortgage Loans [Line Items] |  |
Assets serviced | $ 24.8 | $ 19.4
Percent of aggregate unpaid principal balance | 9.10% | 11.80%
Fair Value GNMA Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 4.70% | 5.40%
Fair Value GNMA Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 1.50% | 1.80%
Fair Value GNMA Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |
Participating Mortgage Loans [Line Items] |  |
Percent of aggregate unpaid principal balance | 2.90% | 4.50%

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- Definition Percentage of financing receivable balance that is past due. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
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