Income Taxes - Components of the company’s current and deferred tax assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Operating loss carryforwards	$ 7,082	$ 4,953
Research credit carryforwards	434	197
Operating lease liability	439
Accrued expenses and other	1,779	1,149
Total deferred tax assets	9,734	6,299
Deferred tax liabilities:
Operating lease right-of-use asset	(422)
Depreciation & amortization	(326)	(163)
Total deferred tax liabilities	(748)	(163)
Valuation allowance	(8,104)	(5,621)
Net deferred tax assets	$ 882	$ 515