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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The aggregate net amount of depreciation, amortization, and accretion recognized during an accounting period. As a noncash item, the net amount is added back to net income when calculating cash provided by or used in operations using the indirect method.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services 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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Supplemental Balance Sheet Information - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,764		$ 3,416
Less: accumulated depreciation	(1,466)		(1,317)
Property and equipment, net	2,298		2,099
Depreciation and amortization	148	$ 87
Scientific equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,315		2,795
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	192		192
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	41		41
Computers and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	48		32
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 168		$ 356