Organization and operations (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	9 Months Ended
	Aug. 08, 2019	Jun. 05, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Aug. 01, 2019	Jul. 01, 2019	Mar. 19, 2019	Dec. 31, 2018
Initial Public Offering
Share value	$ 0.001		$ 0.001	$ 0.001					$ 0.001
Common Stock, Value, Issued			$ 28	$ 28					$ 22
Shares issued	2,700,000
Gross Proceeds From Issuance Of Common Stock	$ 69,000
Net proceeds from issuance of common shares	64,500				$ (53)
stock issuance cost	$ 4,500
Underwritten public offering
Initial Public Offering
Share value	$ 0.001
Shares issued	2,700,000
Gross Proceeds From Issuance Of Common Stock	$ 69,000
Net proceeds from issuance of common shares	64,500			$ 64,529
stock issuance cost	$ 4,500
Underwritten public offering | Common stock
Initial Public Offering
Shares issued			2,732,673	2,732,673
At-the-market offering
Initial Public Offering
Share value								$ 0.001
Common Stock, Value, Issued								$ 50,000
Shares issued		2,200,000
Shares issued (in dollars per share)		$ 22.73
Gross Proceeds From Issuance Of Common Stock		$ 49,700
Net proceeds from issuance of common shares		48,000		$ 48,019
stock issuance cost		$ 1,700
At-the-market offering | Maximum
Initial Public Offering
Common Stock, Value, Issued								$ 50,000
At-the-market offering | Common stock
Initial Public Offering
Shares issued				2,186,163
UmanDiagnostics AB Acquisition [Member]
Initial Public Offering
Capital stock shares outstanding, percent						5.00%	95.00%