Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Leases
Total lease cost	$ 164	$ 222	$ 405	$ 426
Classification of operating leases
Operating lease right-of-use assets	1,567		1,567		$ 1,833
Operating lease liability, current	$ 520		$ 520		538
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current		Other Accrued Liabilities, Current
Operating Lease, Liability, Noncurrent	$ 1,330		$ 1,330		$ 1,574
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent		Other Liabilities, Noncurrent
Lease cost
Operating lease cost	$ 152	161	$ 320	316
Short-term lease cost	12	61	85	110
Total lease cost	$ 164	$ 222	$ 405	426
Lease Term and Discount Rate
Weighted average remaining lease term	3 years 9 months 18 days		3 years 9 months 18 days
Weighted average discount rate	6.90%		6.90%
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases			$ 288	269
Operating lease right-of-use assets obtained in exchange for new operating lease liabilities				$ 393
Minimum
Leases
Initial lease term	1 year		1 year
Maximum
Leases
Initial lease term	7 years		7 years