Summary of Significant Accounting Policies - Concentrations (Details) - item	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total net revenue | Customer 1
Concentrations
Concentration risk (as a percentage)	100.00%	34.00%	90.00%	28.00%
Total net revenue | Customer 2
Concentrations
Concentration risk (as a percentage)		28.00%		28.00%
Total net revenue | Customer 3
Concentrations
Concentration risk (as a percentage)		25.00%		25.00%
Total net revenue | Customer risk | One major pharmaceutical distributors
Concentrations
Number of major distributors	1		1
Total net revenue | Customer risk | Three major pharmaceutical distributors
Concentrations
Number of major distributors		3		3
Total net revenue | Customer risk | Three major pharmaceutical distributors | Minimum
Concentrations
Concentration risk (as a percentage)			10.00%
Total accounts receivable | Customer 1
Concentrations
Concentration risk (as a percentage)			99.60%	35.00%
Total accounts receivable | Customer 2
Concentrations
Concentration risk (as a percentage)				29.00%
Total accounts receivable | Customer 3
Concentrations
Concentration risk (as a percentage)				26.00%