Stock-Based Compensation - Summary of RSU Activity under the 2019 and 2010 Plan (Details) - Equity Incentive Plan 2010 - RSU's - $ / shares	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2020
Number of Shares
Non-vested shares at the beginning of the year	81,000	82,000	103,000	103,000
Granted (in shares)	3,000
Vested (in shares)	(20,000)		(21,000)
Cancelled (in shares)	(4,000)	(1,000)
Non-vested shares at the end of the period	60,000	81,000	82,000	60,000
Weighted Average Grant-Date Fair Value
Weighted average grant date fair value	$ 3.73	$ 3.74	$ 3.75	$ 3.75
RSUs granted	1.87
Vested (in dollars per share)	3.56		3.80
Cancelled (in dollars per shares)	4.00	4.55
Weighted average grant date fair value	$ 3.58	$ 3.73	$ 3.74	$ 3.58