Fair Value Measurement - By Balance Sheet Grouping and Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount for selling costs	10.00%
Financial assets [Abstract]
Securities available-for-sale	$ 326,222	$ 326,222	$ 341,873
Securities held-to-maturity	84,639	84,639	98,261
Financial liabilities [Abstract]
Long-term Federal Home Loan Bank advances	25,110	25,110	25,424
Carrying Value
Financial assets [Abstract]
Cash and due from banks, interest-bearing deposits in banks and federal funds sold	163,123	163,123	82,228
Securities available-for-sale	326,222	326,222	341,873
Securities held-to-maturity	83,739	83,739	98,211
Other investments	12,200	12,200	11,355
Loans, net	1,210,916	1,210,916	1,259,710
Cash surrender value of life insurance policies	14,834	14,834	14,335
Financial liabilities [Abstract]
Non-interest-bearing deposits	428,183	428,183	414,921
Interest-bearing deposits	1,127,752	1,127,752	1,164,509
Securities sold under agreements to repurchase	54,875	54,875	94,461
Short-term Federal Home Loan Bank advances	12,500	12,500
Long-term Federal Home Loan Bank advances	25,110	25,110	25,424
Junior subordinated debentures	22,167	22,167	22,167
Fair Value | Level 1
Financial assets [Abstract]
Cash and due from banks, interest-bearing deposits in banks and federal funds sold	163,123	163,123	82,228
Securities available-for-sale			2,059
Securities held-to-maturity	0	0	0
Other investments	12,200	12,200	11,355
Loans, net	0	0	0
Cash surrender value of life insurance policies	0	0	0
Derivative Asset	0	0	0
Financial liabilities [Abstract]
Non-interest-bearing deposits	0	0	0
Interest-bearing deposits	0	0	0
Securities sold under agreements to repurchase	54,875	54,875	94,461
Short-term Federal Home Loan Bank advances	12,500	12,500
Long-term Federal Home Loan Bank advances	0	0	0
Junior subordinated debentures	0	0	0
Fair Value | Level 2
Financial assets [Abstract]
Cash and due from banks, interest-bearing deposits in banks and federal funds sold	0	0	0
Securities available-for-sale	324,143	324,143	339,814
Securities held-to-maturity	84,639	84,639	98,261
Other investments	0	0	0
Loans, net	0	0	0
Cash surrender value of life insurance policies	14,834	14,834	14,335
Derivative Asset	855	855	989
Financial liabilities [Abstract]
Non-interest-bearing deposits	428,183	428,183	414,921
Interest-bearing deposits	936,173	936,173	1,012,633
Securities sold under agreements to repurchase	0	0	0
Short-term Federal Home Loan Bank advances	0	0
Long-term Federal Home Loan Bank advances	25,215	25,215	25,808
Junior subordinated debentures	22,167	22,167	22,167
Fair Value | Level 3
Financial assets [Abstract]
Cash and due from banks, interest-bearing deposits in banks and federal funds sold	0	0	0
Securities available-for-sale	0	0	0
Securities held-to-maturity	0	0	0
Other investments	0	0	0
Loans, net	1,212,881	1,212,881	1,263,089
Cash surrender value of life insurance policies	0	0	0
Derivative Asset	0	0	0
Financial liabilities [Abstract]
Non-interest-bearing deposits	0	0	0
Interest-bearing deposits	190,407	190,407	150,879
Securities sold under agreements to repurchase	0	0	0
Short-term Federal Home Loan Bank advances	0	0
Long-term Federal Home Loan Bank advances	0	0	0
Junior subordinated debentures	$ 0	$ 0	$ 0
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Period when new appraisals are received		28 days
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Period when new appraisals are received		42 days