Stock Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Shares
Outstanding, beginning of period (in shares)			785,832
Granted (in shares)			583,500
Cancelled or forfeited (in shares)			(32,589)
Expired (in shares)			(481)
Outstanding, end of period (in shares)	1,336,262		1,336,262		785,832
Vested and exercisable (in shares)	482,969		482,969
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)			$ 16.48
Granted (in dollars per share)			5.55
Cancelled or forfeited (in dollars per share)			26.59
Expired (in dollars per share)			32.10
Outstanding at end of year (in dollars per share)	$ 11.46		11.46		$ 16.48
Vested and Exercisable (in dollars per share)	$ 21.82		$ 21.82
Weighted Average Remaining Contractual Term (years)
Outstanding			8 years 3 months 22 days		8 years 1 month 17 days
Vested and Exercisable			6 years 10 months 21 days
Aggregate Intrinsic Value
Outstanding	$ 964		$ 964		$ 470
Vested and Exercisable	$ 227		$ 227
Stock options
Stock Incentive Plans
Exercised (in shares)	0	0	0	0
Aggregate fair value of options vested	$ 300	$ 500	$ 1,000	$ 1,300
Weighted average grant date fair value of options granted (in dollars per share)	$ 4.85	$ 4.10	$ 3.72	$ 3.25
Unrecognized compensation expense related to unvested stock option awards	$ 2,800		$ 2,800
Weighted-average amortization period over which cost is expected to be recognized			2 years 8 months 12 days