Condensed Consolidated Statements of Stockholders' Equity (Parenthetical)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Stock issued for benefit plans (shares)	154,665	104,890	50,987
Shares issued from stock option exercises	0	1,125	63,040
Purchase of treasury shares (shares)	102,673us-gaap_TreasuryStockSharesAcquired	98,020us-gaap_TreasuryStockSharesAcquired	86,812us-gaap_TreasuryStockSharesAcquired
Employee stock purchase plan (shares)	71,825	72,273	42,624
Issuance of restricted stock (shares)	392,292	391,581	375,157

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Number of shares of capital stock issued (purchased by employees) in connection with an employee stock ownership plan.

+ 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

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

Reference 3: 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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 40

-Section 25

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=6418455&loc=d3e16649-113920

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- Definition

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

+ References

+ Details

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- Definition

Number of shares of stock issued during the period that is attributable to transactions involving issuance of stock not separately disclosed.

+ References

No definition available.

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- Definition

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

+ References

+ Details

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- Definition

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

+ References

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