Balance Sheet Components (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Balance Sheet Components [Abstract]
Accrued payroll and related expenses	$ 9,889	$ 13,898
Provision for sales returns	481	359
Accrued professional services	2,290	2,039
Operating lease liability	1,519	1,294
Accrued royalty expense	682	687
Deferred revenue	522	157
Accrued travel expenses	637	590
Accrued clinical expenses	73	99
Accrued other expenses	651	679
Total	$ 16,744	$ 19,802