Commitments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Lessee, Operating Lease, Description [Abstract]
Right-of-use assets	$ 1,485	$ 1,485		$ 0
Lease liabilities	1,506	1,506
Amortization of right-of-use asset		147	$ 0
Operating lease costs	116	227
Cash paid for amounts included in measurement of operating lease liabilities	$ 110	$ 204
Incremental borrowing rate		9.76%
Weighted average remaining lease term	4 years 6 months	4 years 6 months
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remaining in 2019	$ 167	$ 167
2020	436	436
2021	456	456
2022	371	371
2023	242	242
Thereafter	177	177
Total remaining lease payments	1,849	1,849
Less: imputed interest	(343)	(343)
Total lease liabilities	$ 1,506	$ 1,506
Minimum [Member]
Lessee, Operating Lease, Description [Abstract]
Remaining lease term		1 year
Maximum [Member]
Lessee, Operating Lease, Description [Abstract]
Remaining lease term		6 years
Facility One [Member]
Lessee, Operating Lease, Description [Abstract]
Renewal term	2 years	2 years
Carlsbad Facility [Member]
Lessee, Operating Lease, Description [Abstract]
Renewal term	5 years	5 years
ASU 2016-02 [Member]
Lessee, Operating Lease, Description [Abstract]
Right-of-use assets				848
Lease liabilities				848
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Total lease liabilities				$ 848
ASU 2016-02 [Member] | Carlsbad Facility [Member]
Lessee, Operating Lease, Description [Abstract]
Right-of-use assets	$ 784	$ 784
Lease liabilities	784	784
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Total lease liabilities	$ 784	$ 784