Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued compensation	$ 5,360	$ 6,416
Accrued professional fees	153	113
Accrued income tax	956	716
Current operating lease liability	868	1,283
Current finance lease liability	29	50
Royalties	147	365
Accrued liabilities - other	637	426
Contingent liability - General Photonics	0	1,000
Total accrued liabilities	$ 8,150	$ 10,369