Interim Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 10,196	$ 8,180
Preferred stock, par value (dollars per share)	$ 0.1	$ 0.10
Preferred stock, shares authorized (shares)	200,000	200,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	20,000,000	20,000,000
Common stock, shares issued (shares)	6,592,000	6,513,000
Common stock, shares outstanding (shares)	6,360,000	6,281,000
Treasury stock, shares (shares)	232,000	232,000