Disclosures of Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Available-for-sale: [Abstract]
Total available-for-sale securities	$ 619,848	$ 518,848
Impaired Loans Receivable [Abstract]
Carrying amount of loans with a specific allowance		428
Fair value of loans with a specific allowance		294
Specific Allowance		134
Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	619,848	518,848
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	144	64
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	618,052	516,878
Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	1,652	1,906
Fair Value, Measurements, Nonrecurring [Member]
Impaired Loans Receivable [Abstract]
Carrying amount of loans with a specific allowance	8,370
Fair value of loans with a specific allowance	6,938
Specific Allowance	1,432
U.S. Treasury securities and obligations of U.S. government corporations & agencies
Available-for-sale: [Abstract]
Total available-for-sale securities	136,324	90,141
U.S. Treasury securities and obligations of U.S. government corporations & agencies \| Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	136,324	90,141
U.S. Treasury securities and obligations of U.S. government corporations & agencies \| Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
U.S. Treasury securities and obligations of U.S. government corporations & agencies \| Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	136,324	90,141
U.S. Treasury securities and obligations of U.S. government corporations & agencies \| Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Obligations of states and political subdivisions
Available-for-sale: [Abstract]
Total available-for-sale securities	162,705	110,717
Obligations of states and political subdivisions \| Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	162,705	110,717
Obligations of states and political subdivisions \| Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Obligations of states and political subdivisions \| Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	162,705	110,717
Obligations of states and political subdivisions \| Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Mortgage-backed securities
Available-for-sale: [Abstract]
Total available-for-sale securities	314,991	312,054
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,906
Transfers into Level 3	0
Transfers out of Level 3	0
Total gains or losses [Abstract]
Included in net income	0
Included in other comprehensive income (loss)	(174)
Purchases, issuances, sales and settlements [Abstract]
Purchases	0
Issuances	0
Sales	0
Settlements	(80)
Ending balance	1,652
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	0
Mortgage-backed securities \| Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	314,991	312,054
Mortgage-backed securities \| Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Mortgage-backed securities \| Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	314,991	312,054
Mortgage-backed securities \| Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Trust preferred securities
Available-for-sale: [Abstract]
Total available-for-sale securities	1,652	1,906
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	364
Transfers into Level 3	0
Transfers out of Level 3	0
Total gains or losses [Abstract]
Included in net income	0
Included in other comprehensive income (loss)	1,712
Purchases, issuances, sales and settlements [Abstract]
Purchases	0
Issuances	0
Sales	0
Settlements	(170)
Ending balance	1,906
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	0
Trust preferred securities \| Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	1,652	1,906
Trust preferred securities \| Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Trust preferred securities \| Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	0	0
Trust preferred securities \| Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	1,652	1,906
Other securities
Available-for-sale: [Abstract]
Total available-for-sale securities	4,176	4,030
Other securities \| Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	4,176	4,030
Other securities \| Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale: [Abstract]
Total available-for-sale securities	144	64
Other securities \| Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Available-for-sale: [Abstract]
Total available-for-sale securities	4,032	3,966
Other securities \| Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3)
Available-for-sale: [Abstract]
Total available-for-sale securities	$ 0	$ 0

Amount of allowance for credit losses related to recorded investment measured at fair value on a nonrecurring basis.

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Unpaid principal balance of impaired financing receivables, for which there is a related allowance for credit losses, measured at fair value on a nonrecurring basis.

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Amount of investments in debt securities classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized loss realized upon the write-down of available-for-sale securities.

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