Stock Based Compensation - Stock Compensation Expense, Restricted Stock Units (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	$ 0	$ 23	$ 6	$ 50
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	4	0	8
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	5	0	9
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	0	0	0
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	14	6	33
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	1	0	3
Restricted stock | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	0	1	0	3
Series D Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	29	0	55	0
Series D Preferred Stock | Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	14	0	28	0
Series D Preferred Stock | Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	6	0	10	0
Series D Preferred Stock | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	9	0	$ 17	$ 0
Series D Preferred Stock | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	29	55
Series D Preferred Stock | Restricted stock | Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	14	28
Series D Preferred Stock | Restricted stock | Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	6	10
Series D Preferred Stock | Restricted stock | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock compensation expense	$ 9	$ 17