Significant Accounting Policies (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 01, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
GPO administrative fees as percent of purchase volume		3.00%
Deferred costs		$ 2,412		$ 4,300
Patent application costs		(370)	$ (474)
Right of use asset		3,630
Operating lease liability		$ 4,353
Accounting Standards Update 2016-02
Finite-Lived Intangible Assets [Line Items]
Right of use asset	$ 4,300
Rent credit	900
Operating lease liability	5,200
Effect on opening retained earnings	$ 0
Minimum
Finite-Lived Intangible Assets [Line Items]
Typical payment period for customers		30 days
Maximum
Finite-Lived Intangible Assets [Line Items]
Typical payment period for customers		60 days