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Securities Securities (Sales of Securities Held to Maturity) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract] |  |  |
Proceeds from sales | $ 0 | $ 136,719 | $ 0
Amortized cost | 0 | 132,974 | 0
Gross realized gains | 0 | 3,770 | 0
Gross realized losses | 0 | (25) | 0
Tax expense related to security gains/losses | $ 0 | $ (1,311) | $ 0

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- Definition Held to maturity securities sold amortized cost + References No definition available. + Details
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- Definition Held to maturity securities sold security gross realized loss + References No definition available. + Details
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- Definition Tax expense held to maturity security gains + References No definition available. + Details
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- Definition This item represents the gain (loss) realized on the sale of held-to-maturity securities disposed of during the period. Additionally, this item may include, if not separately presented, any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt securities which are being or have been recognized in earnings during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27405-111563 + Details
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- Definition The cash inflow associated with the sale of securities that had been designated as held-to-maturity. Excludes proceeds from maturities, prepayments and calls by the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26853-111562 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585 + Details
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