CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets
Accounts receivable allowance	$ 1,434	$ 1,729
Prepaid and other assets allowance	644	0
Employee loans current allowance	0	0
Noncurrent assets
Employee loans long-term allowance	0	0
Other long-term assets allowance	$ 132	$ 0
Stockholders' equity
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	160,000,000	160,000,000
Common stock, shares issued	51,117,422	50,177,044
Common stock, shares outstanding	51,097,687	50,166,537