Interim Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Accounts Receivable, Allowance for Credit Loss, Current	$ 16,571	$ 15,469
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	24,803,286	24,921,963
Treasury stock, shares	19,982,725	19,864,048