Commitments and Contingencies (Narrative) (Details) $ in Millions		3 Months Ended	6 Months Ended
	Jan. 09, 2017 shareholder	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Option to extend, term			5 years
Rent expense		$ 0.8	$ 1.6
Variable lease cost		0.2	0.4
Deferred rent		0.2	0.2
Lease liability, current		$ 2.0	$ 2.0
Weighted-average remaining lease term		7 years 4 months 24 days	7 years 4 months 24 days
Weighted-average discount rate		22.10%	22.10%
Number of shareholders in litigation | shareholder	2
Minimum
Lessee, Lease, Description [Line Items]
Term of contract		3 years	3 years
Severance payment, prior to change in control			6 months
Severance payment, period following change in control			18 months
Maximum
Lessee, Lease, Description [Line Items]
Term of contract		9 years	9 years
Severance payment, prior to change in control			18 months
Severance payment, period following change in control			24 months