Product revenue reserves and allowances (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Product revenue reserves and allowances
Product revenue reserves and allowances at beginning	$ 121
Credits and payments made	(121)
Trade discounts and allowances
Product revenue reserves and allowances
Product revenue reserves and allowances at beginning	23
Credits and payments made	(23)
Government rebates and other incentives
Product revenue reserves and allowances
Product revenue reserves and allowances at beginning	67
Credits and payments made	(67)
Returns
Product revenue reserves and allowances
Product revenue reserves and allowances at beginning	31
Credits and payments made	$ (31)