Allowance for Credit Losses (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($) loan	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of TDR loans \| loan	5		5
TDR recorded investment	$ 904		$ 914
Partial charge-off of loan amount	$ 349	$ 97
Number of defaulted TDRs \| loan	0		0
Loan defaults on TDRs	$ 0		$ 0
Accruing Impaired Home Equity Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of TDR loans \| loan	1		1
TDR recorded investment	$ 102		$ 102
Nonaccrual Impaired Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of TDR loans \| loan	4		4
TDR recorded investment	$ 802		$ 812
Residential Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Number of TDR loans \| loan	2		2
Partial charge-off of loan amount	$ 151		$ 151
Real estate loans in process of foreclosure	$ 11		$ 0
Consumer Installment Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of TDR loans \| loan	1		1
Partial charge-off of loan amount	$ 2		$ 2
Other Real Estate Owned [Member]
Financing Receivable, Modifications [Line Items]
Real estate loans in process of foreclosure	$ 170		$ 170

Amount of direct write-downs of financing receivables charged against the allowance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

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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=66008989&loc=SL6953676-111524

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The amount of the outstanding recorded investment related to 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 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=65880944

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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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&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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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL49126937-111524

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-Name Accounting Standards Codification
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