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Securities Fair Value Option Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 | Sep. 30, 2017
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Schedule of Fair Value Option Securities [Line Items] |  |  |
Fair Value Option Securities, Fair Value | $ 452,150 | $ 755,054 | $ 819,531
U.S. government agency residential mortgage-backed securities [Member] |  |  |
Schedule of Fair Value Option Securities [Line Items] |  |  |
Fair Value Option Securities, Fair Value | 452,150 | 755,054 | 819,531
Fair Value Option Securities, Net Unrealized Gain or Loss | $ (7,923) | $ (1,877) | $ 1,671

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- Definition Fair value option securities represent securities the Company has elected to carry at fair value and separately identified on the balance sheet with changes in fair value recognized in earnings as they occur. Certain residential mortgage-backed securities issued by US government agencies are held as an economic hedge of changes in the fair value of mortgage servicing rights and related derivative contracts. In addition, other securities may be held to manage interest rate risk or for deferred compensation purposes. Securities held for interest rate risk management may be economically hedged by derivative contracts not designated as hedging instruments effectively modify these fixed rate securities into variable rate securities. + References No definition available. + Details
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- Definition This represents the unrealized holding gain or loss as of the balance sheet date on fair value option mortgage securities. + References No definition available. + Details
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- Definition Schedule of Fair Value Option Securities [Line Items] + References No definition available. + Details
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- Details
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