CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets
Accounts receivable allowance	$ 2,389	$ 2,181
Employee loans current allowance	0	0
Noncurrent assets
Employee loans long-term allowance	$ 0	$ 0
Stockholders' equity
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares )	49,632,642	48,748,298
Common stock, shares outstanding (in shares)	49,623,617	48,303,811