v3.8.0.1

Fair Value - Recorded Amounts of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
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Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | $ 519,364 | $ 509,578
U.S. Treasury Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 493 | 297
Agency Mortgage-backed Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 464,019 | 468,909
Beneficial interest - FHLMC securitization |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 35,852 | 40,372
Fair Value on Recurring Basis |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 519,364 | 509,578
Fair Value on Recurring Basis | U.S. Treasury Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 493 | 297
Fair Value on Recurring Basis | Agency Mortgage-backed Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 464,019 | 468,909
Fair Value on Recurring Basis | Corporate Bonds |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 19,000 |
Fair Value on Recurring Basis | Beneficial interest - FHLMC securitization |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 35,852 | 40,372
Fair Value Measurement Level 1 |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 493 | 297
Fair Value Measurement Level 1 | Fair Value on Recurring Basis |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 493 | 297
Fair Value Measurement Level 1 | Fair Value on Recurring Basis | U.S. Treasury Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 493 | 297
Fair Value Measurement Level 2 |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 483,019 | 468,909
Fair Value Measurement Level 2 | Fair Value on Recurring Basis |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 483,019 | 468,909
Fair Value Measurement Level 2 | Fair Value on Recurring Basis | Agency Mortgage-backed Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 464,019 | 468,909
Fair Value Measurement Level 2 | Fair Value on Recurring Basis | Corporate Bonds |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 19,000 |
Fair Value Measurement Level 3 |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 35,852 | 40,372
Fair Value Measurement Level 3 | Fair Value on Recurring Basis |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | 35,852 | 40,372
Fair Value Measurement Level 3 | Fair Value on Recurring Basis | Beneficial interest - FHLMC securitization |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Investment securities available for sale | $ 35,852 | $ 40,372

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