Loans (Troubled Debt Restructurings on Financing Receivables) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	32	11
Pre-Modification Recorded Investment	$ 4,250	$ 2,333
Post-Modification Recorded Investment	3,918	$ 2,333
Principal deferment collected from government guarantees	503
Capitalized interest and escrow	$ 170
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	3	3
Pre-Modification Recorded Investment	$ 124	$ 736
Post-Modification Recorded Investment	$ 124	$ 736
Commercial \| Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	3	1
Pre-Modification Recorded Investment	$ 124	$ 95
Post-Modification Recorded Investment	$ 124	$ 95
Commercial \| Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	2
Pre-Modification Recorded Investment	$ 0	$ 641
Post-Modification Recorded Investment	$ 0	$ 641
Agricultural and agricultural real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0
Pre-Modification Recorded Investment	$ 0	$ 0
Post-Modification Recorded Investment	$ 0	$ 0
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	29	8
Pre-Modification Recorded Investment	$ 4,126	$ 1,597
Post-Modification Recorded Investment	$ 3,794	$ 1,597
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0
Pre-Modification Recorded Investment	$ 0	$ 0
Post-Modification Recorded Investment	$ 0	$ 0

Financing Receivable, Modifications, Increase (Decrease) In Recorded Investment, Capitalized Interest And Escrow

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- Definition

Financing Receivable, Modifications, Increase (Decrease) In Recorded Investment, Collection of Guarantees

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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