CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
CONDENSED CONSOLIDATED BALANCE SHEETS
Trade accounts receivable, allowance for doubtful accounts (in dollars)	$ 1,714	$ 3,986
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	40,835,651	40,835,651
Common stock, shares outstanding	37,482,297	36,680,469
Treasury stock, shares	3,353,354	4,155,182