Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Condensed Consolidated Balance Sheets
Accounts receivable, accumulated provision for doubtful accounts (in dollars)	$ 6,139	$ 5,171
Common stock, par value (in dollars per share)
Common stock, authorized shares	320,000	320,000
Common stock, shares issued	175,384	175,684
Treasury stock, shares	23,882	24,800

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.

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Face amount per share of no-par value common stock.

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

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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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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.

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