Summary of Significant Accounting Policies - Reconciliation of Liabilities (Details) - Fair value, inputs, level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ 2,600
Settlement of milestone #1 and #2	(2,889)	$ (1,446)
Change in fair value measurement and milestone #2	289
Straight line recognition of liability classified equity award	173
Change in fair value measurement- equity award	93
Change in fair value measurement		846
Ending balance	$ 266	2,600
SafeOp Surgical, Inc.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Contingent consideration liability recorded upon acquisition of SafeOp		$ 3,200