Fair Value Measurement - Assets Recorded at Fair Value and Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for selling costs	10.00%
Available-for-sale securities:
Total available-for-sale securities	$ 316,145	$ 316,145	$ 318,159
Recurring
Available-for-sale securities:
Total available-for-sale securities	316,145	316,145	318,159
Recurring | Level 1
Available-for-sale securities:
Obligations of state and political subdivisions	0	0	0
GSE mortgage-backed securities	0	0	0
Collateralized mortgage obligations: residential	0	0	0
Collateralized mortgage obligations: commercial	0	0	0
Mutual funds	2,125	2,125	2,092
Corporate debt Securities	0	0
Total available-for-sale securities	2,125	2,125	2,092
Derivative Asset	0	0
Recurring | Level 2
Available-for-sale securities:
Obligations of state and political subdivisions	31,521	31,521	31,493
GSE mortgage-backed securities	69,145	69,145	87,038
Collateralized mortgage obligations: residential	196,005	196,005	192,088
Collateralized mortgage obligations: commercial	3,465	3,465	5,448
Mutual funds	0	0	0
Corporate debt Securities	13,884	13,884
Total available-for-sale securities	314,020	314,020	316,067
Derivative Asset	55	55
Recurring | Level 3
Available-for-sale securities:
Obligations of state and political subdivisions	0	0	0
GSE mortgage-backed securities	0	0	0
Collateralized mortgage obligations: residential	0	0	0
Collateralized mortgage obligations: commercial	0	0	0
Mutual funds	0	0	0
Corporate debt Securities	0	0
Total available-for-sale securities	0	0	0
Derivative Asset	0	0
Nonrecurring
Assets and Liabilities Measured on Nonrecurring Basis
Impaired loans	16,033	16,033	17,487
Other real estate	2,317	2,317	4,187
Nonrecurring | Level 1
Assets and Liabilities Measured on Nonrecurring Basis
Impaired loans	0	0	0
Other real estate	0	0	0
Nonrecurring | Level 2
Assets and Liabilities Measured on Nonrecurring Basis
Impaired loans	16,033	16,033	17,487
Other real estate	2,317	2,317	4,187
Nonrecurring | Level 3
Assets and Liabilities Measured on Nonrecurring Basis
Impaired loans	0	0	0
Other real estate	0	0	0
Obligations of state and political subdivisions
Available-for-sale securities:
Total available-for-sale securities	31,521	31,521	31,493
Obligations of state and political subdivisions | Recurring
Available-for-sale securities:
Total available-for-sale securities	31,521	31,521	31,493
GSE mortgage-backed securities
Available-for-sale securities:
Total available-for-sale securities	69,145	69,145	87,038
GSE mortgage-backed securities | Recurring
Available-for-sale securities:
Total available-for-sale securities	69,145	69,145	87,038
Collateralized mortgage obligations: residential
Available-for-sale securities:
Total available-for-sale securities	196,005	196,005	192,088
Collateralized mortgage obligations: residential | Recurring
Available-for-sale securities:
Total available-for-sale securities	196,005	196,005	192,088
Collateralized mortgage obligations: commercial
Available-for-sale securities:
Total available-for-sale securities	3,465	3,465	5,448
Collateralized mortgage obligations: commercial | Recurring
Available-for-sale securities:
Total available-for-sale securities	3,465	3,465	5,448
Mutual funds
Available-for-sale securities:
Total available-for-sale securities	2,125	2,125	2,092
Mutual funds | Recurring
Available-for-sale securities:
Total available-for-sale securities	2,125	2,125	2,092
Corporate debt securities
Available-for-sale securities:
Total available-for-sale securities	13,884	13,884
Corporate debt securities | Recurring
Available-for-sale securities:
Total available-for-sale securities	13,884	$ 13,884
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period when new appraisals are received		28 days
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period when new appraisals are received		42 days
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Available-for-sale securities:
Derivative Asset	$ 55	$ 55	$ 0