Consolidated Balance Sheet Components - Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts and sales returns reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	$ 1,438	$ 215	$ 410
Allowance for doubtful accounts, ending balance	1,784	1,438	215
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	1,115	215	410
Charged to costs and expenses, net of recoveries	315	1,044	418
Deductions (write-offs)	(477)	(144)	(613)
Allowance for doubtful accounts, ending balance	953	1,115	215
Sales returns reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	323	0
Charged to revenue	1,560	677	0
Deductions (write-offs)	(1,052)	(354)	0
Allowance for doubtful accounts, ending balance	$ 831	$ 323	$ 0