Fair Value Measurements - Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial Assets:
Securities available for sale	$ 321,337	$ 346,502
Financial Liabilities:
Other short-term borrowings	24,000	20,000
Level 1
Financial Assets:
Cash and cash equivalents	52,477	53,207
Securities available for sale	0	0
Restricted stock	0	0
Loans held for sale	0	0
Loans, net of allowance	0	0
Bank owned life insurance	0	0
Accrued interest receivable	0	0
Financial Liabilities:
Deposits	0	0
Repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term borrowings		0
Junior subordinated debt	0	0
Accrued interest payable	0	0
Level 2
Financial Assets:
Cash and cash equivalents	0	0
Securities available for sale	321,337	346,502
Restricted stock	6,110	6,224
Loans held for sale	1,639	5,996
Loans, net of allowance	0	0
Bank owned life insurance	18,460	18,163
Accrued interest receivable	5,231	5,083
Financial Liabilities:
Deposits	1,151,068	991,785
Repurchase agreements	10,726	39,166
Other short-term borrowings	24,000	20,000
Long-term borrowings		0
Junior subordinated debt	0	0
Accrued interest payable	674	623
Level 3
Financial Assets:
Cash and cash equivalents	0	0
Securities available for sale	0	0
Restricted stock	0	0
Loans held for sale	0	0
Loans, net of allowance	1,317,737	1,136,961
Bank owned life insurance	0	0
Accrued interest receivable	0	0
Financial Liabilities:
Deposits	376,888	374,774
Repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term borrowings		10,156
Junior subordinated debt	28,358	24,932
Accrued interest payable	0	0
Carrying Value
Financial Assets:
Cash and cash equivalents	52,477	53,207
Securities available for sale	321,337	346,502
Restricted stock	6,110	6,224
Loans held for sale	1,639	5,996
Loans, net of allowance	1,322,522	1,152,020
Bank owned life insurance	18,460	18,163
Accrued interest receivable	5,231	5,083
Financial Liabilities:
Deposits	1,534,726	1,370,640
Repurchase agreements	10,726	39,166
Other short-term borrowings	24,000	20,000
Long-term borrowings		9,980
Junior subordinated debt	27,826	27,724
Accrued interest payable	674	623
Fair Value Balance
Financial Assets:
Cash and cash equivalents	52,477	53,207
Securities available for sale	321,337	346,502
Restricted stock	6,110	6,224
Loans held for sale	1,639	5,996
Loans, net of allowance	1,317,737	1,136,961
Bank owned life insurance	18,460	18,163
Accrued interest receivable	5,231	5,083
Financial Liabilities:
Deposits	1,527,956	1,366,559
Repurchase agreements	10,726	39,166
Other short-term borrowings	24,000	20,000
Long-term borrowings		10,156
Junior subordinated debt	28,358	24,932
Accrued interest payable	$ 674	$ 623