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Concentrations of Credit Risk (Details) - Credit concentration risk $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) customer	Dec. 31, 2015 USD ($)
U.S. Government, its agencies and Government Sponsored Enterprises (GSEs)
Concentration Risk [Line Items]
Concentration risk percentage	72.00%	74.40%
Concentration risk amount | $	$ 299.5	$ 362.6
Loans on real estate
Concentration Risk [Line Items]
Concentration risk percentage	79.00%	80.00%
Loans portfolio
Concentration Risk [Line Items]
Number of major borrowers | customer	0
Concentration risk, threshold for major borrower, percentage	5.00%

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- Definition

Concentration Risk, Percentage, Threshold For Major Borrower

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Number Of Major Borrowers

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- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

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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.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

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-Topic 825
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-Section 50
-Paragraph 21
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