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Capitalized Servicing Assets - Additional Information (Detail) - USD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Apr. 01, 2022 | Dec. 31, 2024 | Dec. 31, 2023
Servicing Assets at Fair Value [Line Items] |  |  |
Purchase of residential mortgage loans |  |  | $ 350
Loans and leases |  | $ 135,581 | $ 134,068
Weighted average discount rates used to estimate fair value of capitalized mortgaged loan servicing assets |  | 12.80% | 14.43%
Residential Mortgage Loans |  |  |
Servicing Assets at Fair Value [Line Items] |  |  |
Fair value of residential loan servicing assets |  | $ 612 | $ 611
Weighted average discount rates used to estimate fair value of capitalized mortgaged loan servicing assets |  | 11.64% | 11.45%
Discounted rate represented weighted-average option-adjusted basis spread point percentage |  | 7.58% | 7.90%
Residential Real Estate |  |  |
Servicing Assets at Fair Value [Line Items] |  |  |
Loans and leases |  |  | $ 19,500
Fair value of residential loan servicing assets | $ 1,100 |  |
Purchase price of servicing rights | $ 12 |  |
Commercial Mortgage Loans |  |  |
Servicing Assets at Fair Value [Line Items] |  |  |
Fair value of residential loan servicing assets |  | $ 194 | $ 193
Weighted average discount rates used to estimate fair value of capitalized mortgaged loan servicing assets |  | 12.80% |

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- Definition Discount rate which is used to value residual cash flows generated by financial assets of a securitization, asset-backed financing arrangement, or similar transfer regardless of when the transfer occurred. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4 + Details
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- Definition Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
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- Definition The cash outflow to obtain servicing rights, which contractually entitle the servicer to receive fees and ancillary revenues for performing billing, collection, disbursement and recordkeeping services in connection with a mortgage portfolio. Rights may be obtained via (1) acquisition or assumption of a servicing obligation that does not relate to financial assets of the servicer or its consolidated affiliates; or (2) by originating mortgage loans and then (a) transferring the loans to a Variable Interest Entity (VIE) in a transaction that meets the necessary transfer and classification requirements, or (b) transferring the loans in a transaction that meets the requirements for sale accounting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 860 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-3 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-13 + Details
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- Definition 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. + References 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 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481229/860-50-50-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481260/860-50-45-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481260/860-50-45-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481260/860-50-45-2 + Details
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