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Capital Requirements - Narrative (Detail) | 9 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2018 | Jan. 01, 2019 | Jan. 01, 2018 | Dec. 31, 2017 | Jan. 01, 2017 | Jan. 01, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] |  |  |  |  |  |
Capital conservation buffer period | 4 years |  |  |  |  |
Capital conservation buffer percentage | 1.875% |  | 0.625% | 1.25% | 0.625% | 0.625%
Capital conservation buffer percentage maintained at bank | 5.25% |  |  | 5.12% |  |
Scenario, Forecast |  |  |  |  |  |
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] |  |  |  |  |  |
Capital conservation buffer percentage |  | 0.625% |  |  |  |

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- Definition Capital conservation buffer percentage maintained at bank. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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