Balance Sheet Components - Schedule of Allowance for Sales Returns (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (17,739)
Ending balance	(10,952)	$ (17,739)
Allowance for Sales Returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(6,907)	(6,916)
Charged to revenue	(6,755)	(19,089)
Utilization of sales return/incentive reserve	9,158	19,098
Ending balance	$ (4,504)	$ (6,907)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

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- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

+ Details

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- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

+ References

+ Details

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