Loans (Schedule of Allowance for Loan Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	$ 14,438	$ 14,929	$ 14,584
Provision for Loan Losses	1,200	0	150
Recoveries	270	473	1,210
Loans Charged-off	(1,100)	(964)	(1,015)
Ending Balance	14,808	14,438	14,929
Commercial and Industrial Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	4,242	4,627	3,983
Provision for Loan Losses	(483)	(451)	732
Recoveries	32	102	111
Loans Charged-off	(66)	(36)	(199)
Ending Balance	3,725	4,242	4,627
Commercial Real Estate Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	6,342	7,273	8,335
Provision for Loan Losses	(846)	(688)	(1,596)
Recoveries	10	107	863
Loans Charged-off	(54)	(350)	(329)
Ending Balance	5,452	6,342	7,273
Agricultural Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	2,115	1,123	946
Provision for Loan Losses	2,000	992	177
Recoveries	1	0	0
Loans Charged-off	(22)	0	0
Ending Balance	4,094	2,115	1,123
Home Equity Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	383	246	239
Provision for Loan Losses	33	160	37
Recoveries	3	10	42
Loans Charged-off	(136)	(33)	(72)
Ending Balance	283	383	246
Consumer Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	230	354	188
Provision for Loan Losses	273	(48)	291
Recoveries	208	236	173
Loans Charged-off	(476)	(312)	(298)
Ending Balance	235	230	354
Residential Mortgage Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	414	622	281
Provision for Loan Losses	245	7	437
Recoveries	16	18	21
Loans Charged-off	(346)	(233)	(117)
Ending Balance	329	414	622
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	712	684	612
Provision for Loan Losses	(22)	28	72
Recoveries	0	0	0
Loans Charged-off	0	0	0
Ending Balance	$ 690	$ 712	$ 684

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, after recoveries, of loans and leases that have been written-off.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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Amount of expense related to estimated loss from loan and lease transactions.

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-Name Accounting Standards Codification
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