Commitments and Contingencies (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) ft² LeaseAgreement	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Operating Leases [Abstract]
Restricted cash	$ 1,525		$ 1,525		$ 1,436
Lease cost [Abstract]
Operating lease cost			775
Total lease cost			775
Maturities of operating lease liabilities [Abstract]
2019 (remaining three months)	344		344
2020	1,150		1,150
2021	894		894
2022	572		572
2023	74		74
Total lease payments	3,033		3,033
Less: interest	(290)		(290)
Total operating lease liabilities	2,743		2,743
Future annual minimum lease payment commitments [Abstract]
2019 (remaining three months)	788		788
2020	2,405		2,405
2021	2,162		2,162
2022	1,876		1,876
2023	1,738		1,738
Thereafter	22,143		22,143
Total	31,112		31,112
Operating lease assets and liabilities [Abstract]
Operating right-of-use assets	2,254		2,254		0
Operating current lease liabilities	1,052		1,052
Operating noncurrent lease liabilities	1,691		1,691		0
Total operating lease liabilities	$ 2,743		2,743
Cash paid for amounts included in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases			$ 838
Weighted-average remaining lease term - operating leases	2 years 8 months 12 days		2 years 8 months 12 days
Weighted-average discount rate - operating leases	7.77%		7.77%
Rent expense	$ 100	$ 100	$ 600	$ 600
Property Subject to Operating Lease [Member]
Operating Leases [Abstract]
Restricted cash	$ 1,000		$ 1,000		$ 1,400
NJ Lease Agreement [Member]
Operating Leases [Abstract]
Area of lease increased by amendment | ft²			11,720
Area of lease | ft²			103,720
Term of lease agreement	15 years		15 years
Number of options to renew lease agreement | LeaseAgreement			2
Term of renewal lease agreement	5 years		5 years
Estimated rent payments			$ 1,200
Percentage of annual increase in base rent			3.00%
Cash security deposit	$ 300		$ 300
Maturities of operating lease liabilities [Abstract]
Total lease payments	$ 29,300		$ 29,300