Revenue, Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue [Abstract]
Lease term	36 months		36 months
Notice period to cancel contract agreement			60 days
Contract with Customer, Liability [Abstract]
Short-term contract liabilities	$ 200		$ 200
Long-term contract liabilities	214		214
Change in Contract with Customer, Liability [Abstract]
Contract liabilities recognized as revenue	36		75
Co-pay reimbursements recorded as reduction of revenue	$ (177)	$ (174)	$ (332)	$ (300)