Balance sheet components - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 68,988	$ 74,343
Trade notes receivable	156	672
Allowance for doubtful accounts	(254)	(264)
Accounts receivable, Net ,Total	$ 68,890	$ 74,751

Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of allowance for credit loss on accounts receivable, classified as current.

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Amount, before allowance, of receivables classified as other, due within one year or the operating cycle, if longer.

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