Fair Value Measurements, By Balance Sheet Grouping (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Financial assets [Abstract]
Interest bearing time deposits with other banks	$ 6,708	$ 6,955
Available-for-sale securities	$ 281,773	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	$ 14,797	17,754
Interest bearing time deposits with other banks	0	0
Available-for-sale securities	1,659	5,899
Loans held for sale	1,581	1,827
Net loans	0	0
Bank owned life insurance	26,389	26,223
Regulatory stock	3,977	5,306
Accrued interest receivable	3,618	4,089
Financial liabilities [Abstract]
Deposits	775,628	740,889
Borrowed funds	6,849	41,330
Accrued interest payable	612	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	280,114	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	6,712	6,960
Available-for-sale securities		0
Net loans	838,299	797,184
Bank owned life insurance	0	0
Regulatory stock	0	0
Accrued interest receivable	0	0
Financial liabilities [Abstract]
Deposits	260,435	263,183
Borrowed funds	38,255	36,095
Accrued interest payable	0
Carrying Amount [Member]
Financial assets [Abstract]
Cash and due from banks	14,797	17,754
Interest bearing time deposits with other banks	6,708	6,955
Available-for-sale securities	281,773	314,017
Loans held for sale	1,581	1,827
Net loans	835,902	790,725
Bank owned life insurance	26,389	26,223
Regulatory stock	3,977	5,306
Accrued interest receivable	3,618	4,089
Financial liabilities [Abstract]
Deposits	1,037,609	1,005,503
Borrowed funds	46,836	79,662
Accrued interest payable	612	720
Fair Value [Member]
Financial assets [Abstract]
Cash and due from banks	14,797	17,754
Interest bearing time deposits with other banks	6,712	6,960
Available-for-sale securities	281,773	314,017
Loans held for sale	1,581	1,827
Net loans	838,299	797,184
Bank owned life insurance	26,389	26,223
Regulatory stock	3,977	5,306
Accrued interest receivable	3,618	4,089
Financial liabilities [Abstract]
Deposits	1,036,063	1,004,072
Borrowed funds	45,104	77,425
Accrued interest payable	$ 612	$ 720