Loans and Allowance for Loan Losses, Troubled Debt Restructurings (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($) Loan Contract Property	Jun. 30, 2017 Loan Contract Property	Jun. 30, 2018 USD ($) Loan Contract Property	Jun. 30, 2017 Loan Contract Property	Dec. 31, 2017 USD ($) Loan
Troubled Debt Restructurings [Abstract]
Number of TDR loans in the portfolio	8		8		10
TDR loans in the portfolio \| $	$ 3.7		$ 3.7		$ 5.6
Number of TDR loans current and performing	5		5		6
Number of Contracts \| Contract	0	0	0	0
Number of TDRs with defaults occurring within 12 months of modification	0	0	0	0
Residential Real Estate [Member]
Troubled Debt Restructurings [Abstract]
Number of foreclosed properties in possession or in process of foreclosure \| Property	0	0	0	0

Number of foreclosed properties in possession or in the process of foreclosure.

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- Definition

The number of troubled debt restructuring loans outstanding in the portfolio.

+ References

No definition available.

+ Details

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- Definition

Represents the number of troubled debt restructuring loans that are current and performing in accordance with modified terms.

+ References

No definition available.

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- Definition

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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- Definition

The amount of the outstanding recorded investment related to 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 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

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- Definition

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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- References

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