Equity Incentive Plans (Summary of Stock Option Activity) (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Equity Incentive Plans [Abstract]
Shares, Balance Beginning	1,275,380
Shares, Granted	241,666
Shares, Forfeited	(42,029)
Shares, Balance Ending	1,475,017	1,275,380
Vested and expected to vest at June 30, 2020	1,475,017
Exercisable at June 30, 2020	455,950
Weighted Average Exercise Price, Outstanding Beginning	$ 7.61
Weighted Average Exercise Price, Granted	3.55
Weighted Average Exercise Price, Forfeited	10.01
Weighted Average Exercise Price, Outstanding Ending	6.74	$ 7.61
Weighted Average Exercise Price, Vested or expected to vest at June 30, 2020	6.74
Weighted Average Exercise Price, Exercisable at June 30, 2020	$ 14.40
Weighted Average Remaining Contractual Term (Years), Outstanding	8 years 4 months 6 days	8 years 9 months 22 days
Weighted Average Remaining Contractual Term (Years), Vested or expected to vest at June 30, 2020	8 years 4 months 6 days
Weighted Average Remaining Contractual Term (Years), Exercisable at June 30, 2020	6 years 8 months 16 days
Aggregate Intrinsic Value, Outstanding Ending	$ 923,000
Aggregate Intrinsic Value, Vested or expected to vest at June 30, 2020	923,000
Aggregate Intrinsic Value, Exercisable at June 30, 2020	$ 242,000