CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts receivable, allowance for doubtful accounts and returns	$ 5,843	$ 4,310
Preferred stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	80,176	79,553
Common stock, shares outstanding	80,176	79,553