Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts receivable, allowance for doubtful accounts	$ 1,945	$ 1,517
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	57,567	56,301
Common stock, shares outstanding	55,285	54,413
Treasury stock, shares	2,282	1,888