Basis of Presentation and Summary of Significant Accounting Policies - Immaterial Error Adjustment (Details) - $ / shares	3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Weighted-average shares outstanding - basic and diluted (in shares)	6,024,680	5,408,124	4,750,993	5,180,221	5,973,906	2,330,180
Net loss per common share - basic and diluted (in dollars per share)	$ (0.69)	$ (0.76)	$ (1.75)	$ (2.40)	$ (2.80)	$ (8.26)
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Weighted-average shares outstanding - basic and diluted (in shares)	5,822,818	5,241,924	4,667,434	5,056,794
Net loss per common share - basic and diluted (in dollars per share)	$ (0.71)	$ (0.79)	$ (1.78)	$ (2.46)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Weighted-average shares outstanding - basic and diluted (in shares)	201,862	166,200	83,559	123,427
Net loss per common share - basic and diluted (in dollars per share)	$ 0.02	$ 0.03	$ 0.03	$ 0.06