Fair Value Measurement, Quantitative Information About Level 3 Fair Value Measurements (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2017	Dec. 31, 2016
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	$ 71,997	$ 67,955
Significant Other Observable Inputs (Level 2) [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	541,107	518,783
Significant Unobservable Inputs (Level 3) [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	3,386	2,873
Corporate Securities Available for Sale [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Market Values [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	$ 3,301	$ 2,785
Unobservable input	Discounted cash flows	Discounted cash flows
Corporate Securities Available for Sale [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Market Values [Member] \| Weighted Average [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Weighted average discount	0.00%	0.00%
Impaired Loans [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Appraised Values [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	$ 85	$ 88
Unobservable input	Age of appraisal, current market conditions, experience within local market, and U.S. Government guarantees	Age of appraisal, current market conditions, experience within local market, and U.S. Government guarantees
Impaired Loans [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Appraised Values [Member] \| Weighted Average [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Weighted average discount	81.00%	81.00%
Other Real Estate Owned [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Appraised Values [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	$ 1,356	$ 1,356
Unobservable input	Age of appraisal, current market conditions and selling costs	Age of appraisal, current market conditions and selling costs
Other Real Estate Owned [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Appraised Values [Member] \| Weighted Average [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Weighted average discount	18.00%	18.00%
Assets [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair value	$ 4,742	$ 4,229

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Description of the inputs and valuation technique(s) used to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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