Commitments and Contingencies - Other (Details) - USD ($)		3 Months Ended		6 Months Ended
	Jan. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 15, 2019
Commitments and Contingencies
Period for which base rent is abated	10 months
Annual base rent per month after abatement	$ 19,650
Percentage of annual increase in lease rent	3.00%
Executed letter of credit	$ 39,000
Total remaining commitment under the amended and restated sublease						$ 2,700,000
Rent expenses operating leases		$ 87,000	$ 101,000	$ 190,000	$ 201,000