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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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of assets held-for-sale that are not part of a disposal group, expected to be sold within a year or the normal operating cycle, if longer.

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The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

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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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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services 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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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Balance Sheet Components - Property (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property and Equipment, net
Property and equipment, gross			$ 56,652	$ 51,626
Less: Accumulated depreciation and amortization			(26,985)	(19,337)
Total Property and Equipment, net			29,667	32,289
Impairment of assets			576	2,138	$ 1,557
Proceeds from sale of impaired machinery and equipment					463
Machinery and equipment
Property and Equipment, net
Property and equipment, gross			31,825	27,303
Impairment of assets				2,100
Proceeds from sale of impaired machinery and equipment	$ 200	$ 500
Asset held for sale		$ 200			200
Machinery and equipment \| Cost of product revenues
Property and Equipment, net
Impairment of assets			600	1,900	$ 1,000
Machinery and equipment \| General and administrative expense
Property and Equipment, net
Impairment of assets				200
Machinery and equipment \| Maintenance service contract
Property and Equipment, net
Impairment of assets				300
Furniture and fixtures
Property and Equipment, net
Property and equipment, gross			$ 1,216	1,087
Useful Life			3 years
Computer equipment
Property and Equipment, net
Property and equipment, gross			$ 1,958	861
Useful Life			3 years
Capitalized software held for internal use
Property and Equipment, net
Property and equipment, gross			$ 4,465	2,172
Useful Life			3 years
Leasehold improvements
Property and Equipment, net
Property and equipment, gross			$ 10,691	10,444
Construction-in-process
Property and Equipment, net
Property and equipment, gross			$ 6,497	$ 9,759
Minimum \| Machinery and equipment
Property and Equipment, net
Useful Life			3 years
Maximum \| Machinery and equipment
Property and Equipment, net
Useful Life			5 years