Loans (Troubled debt restructuring) (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($) loan	Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	1	8	11	25
Pre- Modification Recorded Investment	$ 92	$ 1,174	$ 2,098	$ 3,108
Post- Modification Recorded Investment	$ 94	$ 1,174	$ 1,808	$ 3,108
With Payment Defaults During the
Number of Loans \| loan	4	5	10	8
Recorded Investment	$ 418	$ 1,221	$ 1,598	$ 1,480
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0	0	3
Pre- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 131
Post- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 131
With Payment Defaults During the
Number of Loans \| loan	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Commercial \| Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0	0	3
Pre- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 131
Post- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 131
With Payment Defaults During the
Number of Loans \| loan	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Commercial \| Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0	0	0
Pre- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
With Payment Defaults During the
Number of Loans \| loan	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Agricultural and agricultural real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0	0	0
Pre- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
With Payment Defaults During the
Number of Loans \| loan	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	1	8	11	22
Pre- Modification Recorded Investment	$ 92	$ 1,174	$ 2,098	$ 2,977
Post- Modification Recorded Investment	$ 94	$ 1,174	$ 1,808	$ 2,977
With Payment Defaults During the
Number of Loans \| loan	4	5	10	8
Recorded Investment	$ 418	$ 1,221	$ 1,598	$ 1,480
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	0	0	0	0
Pre- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Investment	$ 0	$ 0	$ 0	$ 0
With Payment Defaults During the
Number of Loans \| loan	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0

Financing Receivable, Subsequent Default [Abstract]

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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.

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

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

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Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

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