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Contingent Liabilities and Guarantees - Narrative (Details) - USD ($) $ in Millions | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2026 | Mar. 31, 2026 | Dec. 31, 2025 | Jun. 30, 2025 | Mar. 31, 2025 | Dec. 31, 2024
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Reserve for potential losses | $ 277 | $ 296 | $ 313 | $ 297 | $ 278 | $ 290
Standby letters of credit |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Remaining weighted-average life of standby letters of credit (in years) | 2 years 1 month 6 days |  |  |  |  |
Recourse agreement with FNMA |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Weighted-average remaining term for outstanding commercial mortgage loans (in years) | 5 years 6 months |  |  |  |  |
Unpaid principal balance outstanding of loans sold | $ 25,100 |  |  |  |  |
Maximum potential amount of undiscounted future payments possibly required as percentage of principal balance of loans outstanding (as a percent) | 32.70% |  |  |  |  |
Reserve for potential losses | $ 62 |  |  |  |  |
Residential mortgage reserve |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Unpaid principal balance outstanding of loans sold | $ 11,400 |  |  |  |  |
Maximum potential amount of undiscounted future payments possibly required as percentage of principal balance of loans outstanding (as a percent) | 30.00% |  |  |  |  |
Liability for estimated repurchase obligations on loans sold | $ 7 |  |  |  |  |
Written options |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Weighted average life of written put options (in years) | 1 year 3 months 18 days |  |  |  |  |
Minimum | Standby letters of credit |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Remaining actual life of standby letters of credit (in years) | 1 year |  |  |  |  |
Minimum | Low |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Guarantee obligations (as a percent) | 0.00% |  |  |  |  |
Minimum | Moderate |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Guarantee obligations (as a percent) | 30.00% |  |  |  |  |
Minimum | High |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Guarantee obligations (as a percent) | 70.00% |  |  |  |  |
Maximum | Standby letters of credit |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Remaining actual life of standby letters of credit (in years) | 10 years |  |  |  |  |
Maximum | Low |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Guarantee obligations (as a percent) | 30.00% |  |  |  |  |
Maximum | Moderate |  |  |  |  |  |
Commitments, Contingencies and Guarantees [Line Items] |  |  |  |  |  |
Guarantee obligations (as a percent) | 70.00% |  |  |  |  |

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- Definition Amount, including accrued interest, to be repaid to counterparty to repurchase agreement when carrying amount or market value if higher, of security or other asset sold under repurchase agreement exceeds 10 percent of total assets. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480088/860-10-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481444/860-30-45-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(m)(1)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(m)(1)(ii)(A)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
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