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Investment Securities - Narrative (Details) - Investment Securities [Member] - USD ($) | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Debt Securities, Available-for-sale [Line Items] |  |
Average percent of amortized cost for securities in unrealized loss positions for more than 12 months | 99.50% |
Other-than-temporary impairment | $ 0 | $ 0

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- Definition Available-for-sale securities in a loss position for more than 12 months, qualitative disclosure, percent of amortized cost + References No definition available. + Details
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Period Type: | instant

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- Definition Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + 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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