Business combinations (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Aug. 01, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jul. 01, 2019
Assets (liabilities) acquired:
Goodwill		$ 9,390		$ 9,390		$ 9,353
Revenue		13,130	$ 13,536	28,857	$ 25,872
Net loss		(12,302)	(10,563)	(23,912)	(19,968)
Revenue (unaudited)			13,775		26,735
Pre-tax loss (unaudited)			(9,830)		(18,856)
UmanDiagnostics AB Acquisition
Fair value of consideration transferred:
Cash	$ 15,700
Common stock shares consideration	191,152
Common stock	$ 5,500
Capital stock shares outstanding, percent	95.00%						5.00%
Cash and stock paid	$ 21,217
Cash and cash equivalents acquired	1,221
Purchase price, net	19,996
Assets (liabilities) acquired:
Accounts receivable	638
Inventory	1,680
Prepaids and other current assets	114
Property and equipment	33
Intangibles	13,450
Goodwill	8,111
Accounts payable	(20)
Accrued expense and other current liabilities	(871)
Deferred tax liabilities	(3,139)
Total	$ 19,996
Revenue		400		1,200
Net loss				600
Transaction costs		0	$ 900	$ 0	$ 900
UmanDiagnostics AB Acquisition | Maximum
Assets (liabilities) acquired:
Net loss		$ 100