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Employee Benefit Plans (Schedule of Restricted Stock Plan) (Details) - 2008 Restricted Stock Plan [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Balance	147,000	148,000	127,000
Granted	22,000	24,000	33,000
Vested	(20,000)	(25,000)	(12,000)
Forfeited	(2,000)
Amortization of Compensation Expense
Balance	147,000	147,000	148,000
Unearned compensation
Balance	$ 1,764	$ 1,696	$ 1,483
Granted	799	750	741
Vested
Forfeited	(54)
Amortization of Compensation Expense	(724)	(682)	(528)
Balance	$ 1,785	$ 1,764	$ 1,696
Weighted Average Grant Price
Granted	$ 36.95	$ 30.85	$ 22.65

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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