Select Condensed Consolidated Balance Sheet Details - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 64,754	$ 66,935
Less accumulated depreciation and amortization	(51,933)	(53,700)
Property and equipment, net	$ 12,821	13,235
Surgical instruments
Property, Plant and Equipment [Line Items]
Useful lives	4 years
Property and equipment, gross	$ 52,441	54,848
Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful lives	7 years
Property and equipment, gross	$ 5,993	5,971
Computer equipment
Property, Plant and Equipment [Line Items]
Useful lives	3 years
Property and equipment, gross	$ 3,307	3,104
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Property and equipment, gross	$ 1,195	1,155
Leasehold improvements
Property, Plant and Equipment [Line Items]
Various useful lives of leasehold improvements	various
Property and equipment, gross	$ 1,765	1,765
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 53	$ 92

Various useful life of property and equipment.

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- Definition

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

+ References

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- Definition

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.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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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.

+ References

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- Definition

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.

+ References

No definition available.

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