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Derivatives and Balance Sheet Offsetting (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Derivative [Line Items] |  |  |
Gain (Loss) on Derivative Instruments, Net, Pretax | $ 8 | $ 16 | $ 16
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 61,094 |  |
Secured Borrowings, Gross, Difference, Amount | 0 |  |
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative, Notional Amount | 366,700 | 384,700 |
Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Contracts [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset | 7,033 | 6,707 |
Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Contracts [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liability, Fair Value, Gross Liability | 7,033 | $ 6,714 |
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 | 61,094 |  |
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] | Maturity Overnight [Member] |  |  |
Derivative [Line Items] |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 61,094 |  |
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] | Maturity Less than 30 Days [Member] |  |  |
Derivative [Line Items] |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 0 |  |
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] | Maturity 30 to 90 Days [Member] |  |  |
Derivative [Line Items] |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 0 |  |
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] | Maturity Greater than 90 Days [Member] |  |  |
Derivative [Line Items] |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | $ 0 |  |

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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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- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
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