Loans (Schedule of Allowance for Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	$ 15,166	$ 15,161	$ 14,808	$ 14,438
Provision for Loan Losses	350	350	850	1,200
Recoveries	118	73	212	129
Loans Charged-off	(314)	(280)	(550)	(463)
Ending Balance	15,320	15,304	15,320	15,304
Commercial and Industrial Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	3,612	4,346	3,725	4,242
Provision for Loan Losses	62	(180)	(53)	(75)
Recoveries	7	24	9	28
Loans Charged-off	(9)	0	(9)	(5)
Ending Balance	3,672	4,190	3,672	4,190
Commercial Real Estate Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	5,696	6,463	5,452	6,342
Provision for Loan Losses	(259)	68	19	188
Recoveries	34	2	39	3
Loans Charged-off	(155)	0	(194)	0
Ending Balance	5,316	6,533	5,316	6,533
Agricultural Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	4,361	2,529	4,094	2,115
Provision for Loan Losses	468	175	735	589
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	4,829	2,704	4,829	2,704
Home Equity Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	299	352	283	383
Provision for Loan Losses	16	9	33	40
Recoveries	2	0	2	1
Loans Charged-off	(17)	(11)	(18)	(74)
Ending Balance	300	350	300	350
Consumer Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	244	230	235	230
Provision for Loan Losses	54	66	172	93
Recoveries	67	43	127	88
Loans Charged-off	(111)	(97)	(280)	(169)
Ending Balance	254	242	254	242
Residential Mortgage Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	348	531	329	414
Provision for Loan Losses	19	196	38	351
Recoveries	8	4	35	9
Loans Charged-off	(22)	(172)	(49)	(215)
Ending Balance	353	559	353	559
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	606	710	690	712
Provision for Loan Losses	(10)	16	(94)	14
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	$ 596	$ 726	$ 596	$ 726

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

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of expense related to estimated loss from loan and lease transactions.

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