Fair Value Measurements, By Balance Sheet Grouping (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financial assets [Abstract]
Interest bearing time deposits with other banks	$ 10,031	$ 6,955
Available-for-sale securities	$ 263,588	314,017
Financial liabilities [Abstract]
Consideration period for recognition of cash and due from banks	90 days
Consideration period for recognition of accrued interest receivable and payable	90 days
Level I [Member]
Financial assets [Abstract]
Cash and due from banks	$ 13,815	17,754
Interest bearing time deposits with other banks	0	0
Available-for-sale securities	1,936	5,899
Loans held for sale	1,431	1,827
Net loans	0	0
Bank owned life insurance	26,722	26,223
Regulatory stock	4,884	5,306
Accrued interest receivable	3,786	4,089
Financial liabilities [Abstract]
Deposits	792,133	740,889
Borrowed funds	32,960	41,330
Accrued interest payable	731	720
Level II [Member]
Financial assets [Abstract]
Cash and due from banks	0	0
Interest bearing time deposits with other banks	0	0
Available-for-sale securities	261,652	308,118
Net loans	0	0
Bank owned life insurance	0	0
Regulatory stock	0	0
Accrued interest receivable	0	0
Financial liabilities [Abstract]
Deposits	0	0
Borrowed funds	0	0
Accrued interest payable	0	0
Level III [Member]
Financial assets [Abstract]
Cash and due from banks	0	0
Interest bearing time deposits with other banks	10,038	6,960
Available-for-sale securities		0
Net loans	894,706	797,184
Bank owned life insurance	0	0
Regulatory stock	0	0
Accrued interest receivable	0	0
Financial liabilities [Abstract]
Deposits	258,229	263,183
Borrowed funds	39,005	36,095
Accrued interest payable	0
Carrying Amount [Member]
Financial assets [Abstract]
Cash and due from banks	13,815	17,754
Interest bearing time deposits with other banks	10,031	6,955
Available-for-sale securities	263,588	314,017
Loans held for sale	1,431	1,827
Net loans	896,715	790,725
Bank owned life insurance	26,722	26,223
Regulatory stock	4,884	5,306
Accrued interest receivable	3,786	4,089
Financial liabilities [Abstract]
Deposits	1,052,105	1,005,503
Borrowed funds	73,628	79,662
Accrued interest payable	731	720
Fair Value [Member]
Financial assets [Abstract]
Cash and due from banks	13,815	17,754
Interest bearing time deposits with other banks	10,038	6,960
Available-for-sale securities	263,588	314,017
Loans held for sale	1,431	1,827
Net loans	894,706	797,184
Bank owned life insurance	26,722	26,223
Regulatory stock	4,884	5,306
Accrued interest receivable	3,786	4,089
Financial liabilities [Abstract]
Deposits	1,050,362	1,004,072
Borrowed funds	71,965	77,425
Accrued interest payable	$ 731	$ 720