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Securities Held-to-Maturity - Schedule of Securities Held-to-Maturity (Detail) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
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Schedule of Held-to-maturity Securities [Line Items] |  |
Federal agency debt instruments (amortized cost) | $ 20,136 | $ 20,180
Federal Agency [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Federal agency debt instruments (amortized cost) | $ 20,136 | $ 20,180

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- Definition Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity). + References No definition available. + Details
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Balance Type: | debit
Period Type: | instant

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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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Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |