Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets [Abstract]
Accounts receivable, reserves	$ 4,306	$ 3,533
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	120,000,000us-gaap_CommonStockSharesAuthorized	120,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	101,947,000us-gaap_CommonStockSharesIssued	101,188,000us-gaap_CommonStockSharesIssued
Deferred stock units, outstanding	118,000	122,000
Treasury stock, shares	54,574,000us-gaap_TreasuryStockShares	49,649,000us-gaap_TreasuryStockShares

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.4)

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Total number of shares of other common stock instruments held by shareholders, such as exchangeable shares. May be all or portion of the number of common shares authorized.

+ References

No definition available.

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- Definition

Face amount or stated value per share of common stock.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

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-Name Regulation S-X (SX)

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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- Definition

Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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

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-Name Regulation S-X (SX)

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