Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, chargebacks, allowance for doubtful accounts, and other deductions (in dollars)	$ 3,795	$ 155
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	59,894,362	42,342,706
Common Stock, shares outstanding	58,221,442	40,685,786
Treasury stock, shares	1,672,920	1,656,920