Interim Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Allowance for Doubtful Accounts Receivable, Current	$ 15,190	$ 15,961
Shareholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000us-gaap_PreferredStockSharesAuthorized	10,000,000us-gaap_PreferredStockSharesAuthorized
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000us-gaap_CommonStockSharesAuthorized	125,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	44,786,011us-gaap_CommonStockSharesIssued	44,786,011us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	27,967,560us-gaap_CommonStockSharesOutstanding	28,243,007us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	16,818,451us-gaap_TreasuryStockShares	16,543,004us-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.

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