Condensed Consolidated Balance Sheets (Parenthetical) (unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, chargebacks and other deductions (in dollars)	$ 14,858	$ 14,394
Provision for credit losses (in dollars)	$ 130	$ 124
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	83,298,263	83,231,063
Common Stock, shares outstanding	81,625,343	81,558,143
Treasury stock, shares	1,672,920	1,672,920