Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 5,075	$ 4,578
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares issued	27,970,331	27,192,154
Common stock, shares outstanding	27,970,331	27,192,154

Amount of allowance for credit loss on accounts receivable, classified as current.

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