CONDENSED CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 7,567	$ 4,963
Preferred stock, par value per share (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized	250,000	250,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	60,870,749	59,979,853
Common stock, shares outstanding	60,870,749	59,979,853
Treasury stock, shares	6,374,882	6,374,882