CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Accounts receivable, allowance	$ 5,186	$ 4,404
Stockholders’ equity:
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	75,000,000	75,000,000
Common Stock, shares issued (in shares)	52,605,301	51,386,693
Common Stock: shares outstanding (in shares)	52,605,301	51,386,693