Summary of Significant Accounting Policies - Concentration of Revenue and Customers (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) customer item	Jun. 30, 2020 USD ($) customer	Jun. 30, 2021 USD ($) customer item	Jun. 30, 2020 USD ($) customer
Estimated total revenue from major customers
Number of geographical markets | item	2		2
Revenues	$ 3,289	$ 261	$ 6,135	$ 297
Payment period			60 days
Revenue | Ascensia
Estimated total revenue from major customers
Number of customers | customer	1		1
Revenue | Roche
Estimated total revenue from major customers
Number of customers | customer		1		1
Revenue | Customer Concentration Risk | Ascensia
Estimated total revenue from major customers
Percentage of total revenue	87.00%		85.00%
Revenue | Customer Concentration Risk | Roche
Estimated total revenue from major customers
Percentage of total revenue		17.00%		17.00%
Revenue | Geographic Concentration Risk
Estimated total revenue from major customers
Percentage of total revenue	100.00%	100.00%	100.00%	100.00%
Revenues	$ 3,289	$ 261	$ 6,135	$ 297
Outside of the United States | Revenue | Geographic Concentration Risk
Estimated total revenue from major customers
Percentage of total revenue	70.20%	21.10%	78.90%	22.60%
Revenues	$ 2,310	$ 55	$ 4,843	$ 67
United States | Revenue | Geographic Concentration Risk
Estimated total revenue from major customers
Percentage of total revenue	29.80%	78.90%	21.10%	77.40%
Revenues	$ 979	$ 206	$ 1,292	$ 230