Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts receivable, allowance	$ 1,407	$ 748
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000	50,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	117,119	116,764
Common stock, shares outstanding	117,119	116,764