Fair Value (Additional Information) (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan held for sale, at fair value		$ 12,967,000		$ 12,967,000		$ 10,762,000
Contractual principal balance of Loan held for sale		12,728,000		12,728,000		10,559,000
Difference in amount of loan held for sale		239,000		239,000		203,000
Impaired loans, carrying amount	[1]	1,794,000		1,794,000		3,610,000
Valuation allowance for loans losses		459,000		459,000		1,202,000
Cost of real estate sales		75,000	$ 0	75	$ 0	0
Other real estate, carrying value		0		0		0
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		732,911,000		732,911,000		637,840,000
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		8,011,000		8,011,000		9,373,000
Obligations of State and Political Subdivisions
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total gains/loss included in earnings attributable to other changes in fair value		0	25,000	38,000	(20,000)
Obligations of State and Political Subdivisions | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		247,210,000		247,210,000		203,628,000
Total gains/loss included in earnings attributable to other changes in fair value		0	25,000	38,000	(20,000)
Obligations of State and Political Subdivisions | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		7,658,000		7,658,000		9,020,000
Equity Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total gains/loss included in earnings attributable to interest income		0	0	0	0
Equity Securities | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		353,000		353,000		353,000
Total gains/loss included in earnings attributable to other changes in fair value		0	0	0	0
Equity Securities | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities		353,000		353,000		353,000
Commercial Real Estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans, carrying amount		1,694,000		1,694,000		2,148,000
Valuation allowance for loans losses		459,000		459,000		1,173,000
Increase (decrease) to provision for loan losses		$ 197,000	$ 78,000	$ 222,000	$ 113,000	$ (286,000)

[1] Unpaid Principal Balance is the remaining contractual payments gross of partial charge-offs.