Contractual Commitments and Contingencies - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2017 claim	Aug. 18, 2015 claim	Jul. 10, 2015 claim	Jun. 29, 2015 claim
Loss Contingencies [Line Items]
Lease expiration period			6 years
Rent expense | $	$ 403	$ 453	$ 1,244	$ 1,311
Pending Litigation
Loss Contingencies [Line Items]
Number of patent challenged grounds (claim)					4
Pending Litigation | Bone Bank Action
Loss Contingencies [Line Items]
Number of patent challenged grounds (claim)							5	7
Opinion allowing a review of patent (claim)							2
Pending Litigation | Liventa Action, 701 Patent
Loss Contingencies [Line Items]
Number of patent challenged grounds (claim)						6
Pending Litigation | Liventa Action, 437 Patent
Loss Contingencies [Line Items]
Number of patent challenged grounds (claim)						7
Opinion allowing a review of patent (claim)						1
Standby Letters of Credit
Loss Contingencies [Line Items]
Standby letters of credit | $	$ 52		$ 52