Balance Sheet Components (Inventories, Property and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventories
Finished goods	$ 33,050	$ 24,138
Component parts	4,025	1,880
Work-in-process	96	213
Total inventories	37,171	26,231
Property and equipment, net
Property and equipment, gross	23,537	19,165
Less: accumulated depreciation	(16,200)	(12,702)
Property and equipment, net	7,337	6,463
Computer equipment and software
Property and equipment, net
Property and equipment, gross	5,030	3,855
Manufacturing tooling and test equipment
Property and equipment, net
Property and equipment, gross	4,894	4,216
Lab and warehouse equipment
Property and equipment, net
Property and equipment, gross	4,869	3,649
Leasehold improvements
Property and equipment, net
Property and equipment, gross	3,960	3,438
Furniture and fixtures
Property and equipment, net
Property and equipment, gross	3,698	3,254
Other
Property and equipment, net
Property and equipment, gross	$ 1,086	$ 753

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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