Allowance for Credit Losses (Recorded Investments in Troubled Debt Restructured Loans) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Pre-modification outstanding recorded investment	$ 942	$ 942
Post-modification outstanding recorded investment	1,073	1,073
Recorded Investment	904	914
Residential Mortgage [Member]
Pre-modification outstanding recorded investment	754	754
Post-modification outstanding recorded investment	883	883
Recorded Investment	717	726
Consumer: Home Equity [Member]
Pre-modification outstanding recorded investment	148	148
Post-modification outstanding recorded investment	148	148
Recorded Investment	148	148
Consumer: Other [Member]
Pre-modification outstanding recorded investment	40	40
Post-modification outstanding recorded investment	42	42
Recorded Investment	$ 39	$ 40

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

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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- Definition

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

+ References

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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://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
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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