Other Expense - Schedule of Other Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Income And Expenses [Abstract]
Interest income	$ 9	$ 7	$ 24	$ 48
Interest expense	(111)	(242)	(253)	(518)
Change in fair value of derivative liability		(236)	0	(556)
Realized gain on disposal of equipment			44	(8)
Total other income (expenses)	$ (102)	$ (471)	$ (185)	$ (1,026)