Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014
Retained Earnings [Member]
Cash dividend per share	$ 0.39	$ 0.36
Treasury Stock [Member]
Issued treasury shares to finance acquisition	660,998
Purchase of common stock, shares	373,594	334,630

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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Number of shares that have been repurchased during the period and are being held in treasury.

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