Interim Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Allowance for Doubtful Accounts Receivable, Current	$ 14,822	$ 14,856
Shareholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	44,786,011	44,786,011
Common stock, shares outstanding	29,220,329	29,487,075
Treasury stock, shares	15,565,682	15,298,936