Stockholders' Equity - Restricted Stock Units (Details)	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Restricted Stock Units*
Outstanding at beginning of period (in shares) | shares	155,031
Granted (in shares) | shares	89,400
Canceled/forfeited (in shares) | shares	(16,921)
Outstanding at end of period (in shares) | shares	227,510
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 5.23
Granted (in dollars per share) | $ / shares	1.55
Canceled/forfeited (in dollars per share) | $ / shares	11.34
Outstanding at end of period (in dollars per share) | $ / shares	$ 3.33
Weighted Average Remaining Contractual Life (in years)
Outstanding at end of period	7 years 9 months 18 days
Restricted Stock Units
Restricted Stock Units*
Outstanding at beginning of period (in shares) | shares	6,603
Granted (in shares) | shares	16,000
Released (in shares) | shares	(4,068)
Canceled/forfeited (in shares) | shares	(1)
Outstanding at end of period (in shares) | shares	18,534
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 13.17
Granted (in dollars per share) | $ / shares	1.50
Released (in dollars per share) | $ / shares	13.65
Canceled/forfeited (in dollars per share) | $ / shares	12.40
Outstanding at end of period (in dollars per share) | $ / shares	$ 2.99
Weighted Average Remaining Contractual Life (in years)
Outstanding at end of period	8 years 6 months