Note 6 - Property and Equipment, Net - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, gross	$ 13,259	$ 8,314
Less accumulated depreciation	(6,115)	(5,550)
Property and equipment, net	7,144	2,764
Laboratory Equipment [Member]
Property and equipment, gross	2,951	2,493
Leasehold Improvements [Member]
Property and equipment, gross	5,663	2,766
Office Equipment Furniture and Fixtures [Member]
Property and equipment, gross	3,019	2,205
Software and Software Development Costs [Member]
Property and equipment, gross	1,626	756
Construction in Progress [Member]
Property and equipment, gross		$ 94

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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