CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement Of Stockholders Equity [Abstract]
Common stock dividends, per share	$ 0.22	$ 0.18
Stock option plan, shares	5,752	6,671
Employee stock purchase plan, shares	6,663	5,650
Restricted stock, shares	27,945	41,140
Treasury Stock, Shares, Acquired	351,369us-gaap_TreasuryStockSharesAcquired

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

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.

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Number of share options (or share units) exercised during the current period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.28,29)

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-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(2)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

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

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