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Commitments, Contingencies and Guarantees - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Jun. 30, 2022 | Dec. 31, 2021 | Jun. 30, 2021 | Dec. 31, 2020
Commitments and Contingencies Disclosure [Line Items] |  |  |  |  |  |  |  |
ACL for off-balance sheet credit exposures | $ 3,088,000 | $ 2,588,000 | $ 3,088,000 | $ 2,588,000 | $ 3,088,000 | $ 2,588,000 | $ 3,588,000 | $ 5,588,000
Provision for off-balance sheet credit exposures |  | (1,000,000) | 500,000 | (3,000,000) |  |  |  |
Accrued Expenses and Taxes [Member] |  |  |  |  |  |  |  |
Commitments and Contingencies Disclosure [Line Items] |  |  |  |  |  |  |  |
ACL for off-balance sheet credit exposures | 3,100,000 |  | 3,100,000 |  |  | $ 2,600,000 |  |
Provision for Credit Losses [Member] |  |  |  |  |  |  |  |
Commitments and Contingencies Disclosure [Line Items] |  |  |  |  |  |  |  |
Provision for off-balance sheet credit exposures | $ 0 | $ (1,000,000.0) | $ (500,000) | $ (3,000,000.0) |  |  |  |

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- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=121611286&loc=d3e11927-110247 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82919202-210446 + Details
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- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 + Details
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