Balance Sheet Details - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 32,362	$ 32,112
Less accumulated amortization	(26,651)	(23,306)
Intangible assets, net	5,711	8,806
Amortization of intangible assets	1,600	3,000	$ 2,200
Impairment of intangible assets	1,700
Developed product technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	13,876	13,876
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 1,004	1,004
License agreements
Finite-Lived Intangible Assets [Line Items]
Useful lives	2 years
Intangible assets, Gross	$ 5,265	5,015
License agreements | Biologic product
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	300
License agreements | Epicage Interbody Fusion Device
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	500	900
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 732	732
Customer-related
Finite-Lived Intangible Assets [Line Items]
Useful lives	8 years
Intangible assets, Gross	$ 7,458	7,458
Distribution network
Finite-Lived Intangible Assets [Line Items]
Useful lives	8 years
Intangible assets, Gross	$ 4,027	4,027
Physician education programs | Discontinued operations, disposed of by sale | International operations
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets		$ 900