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Derivatives and Balance Sheet Offsetting (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Derivative [Line Items] |  |  |  |  |
Gain (Loss) on Derivative Instruments, Net, Pretax | $ 6 | $ 9 | $ 12 | $ 2 |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 40,933 |  | 40,933 |  |
Secured Borrowings, Gross, Difference, Amount | 0 |  | 0 |  |
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 40,933 |  | 40,933 |  |
Maturity Overnight [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 15,933 |  | 15,933 |  |
Maturity Less than 30 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 0 |  | 0 |  |
Maturity 30 to 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 0 |  | 0 |  |
Maturity Greater than 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 25,000 |  | 25,000 |  |
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Derivative, Notional Amount | 380,000 |  | 380,000 |  | $ 309,300
Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Contracts [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Fair value of asset derivative instruments | 8,992 |  | 8,992 |  | 9,012
Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Contracts [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Fair value of liability derivative instruments | $ 9,004 |  | $ 9,004 |  | $ 9,036

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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