Consolidated Balance Sheet Components - Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts and sales returns reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	$ 215	$ 410	$ 412
Allowance for doubtful accounts, ending balance	1,438	215	410
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	215	410	412
Charged to costs and expenses	1,044	418	46
Deductions (write-offs)	(144)	(613)	(48)
Allowance for doubtful accounts, ending balance	1,115	215	410
Sales returns reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts, beginning balance	0	0
Charged to revenue	677	0	0
Deductions (write-offs)	(354)	0	0
Allowance for doubtful accounts, ending balance	$ 323	$ 0	$ 0