Basis of Presentation and Summary of Significant Accounting Policies - Concentration and Significant Customer Information (Details) - facility	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue from Contract with Customer, Product and Service Benchmark | Customer Concentration Risk | McKesson Corporation
Concentrations and Significant Customer Information
Concentration risk	35.00%	26.00%	36.00%	27.00%
Revenue from Contract with Customer, Product and Service Benchmark | Customer Concentration Risk | AmerisourceBergen Drug Corporation
Concentrations and Significant Customer Information
Concentration risk	28.00%	27.00%	27.00%	27.00%
Revenue from Contract with Customer, Product and Service Benchmark | Customer Concentration Risk | Cardinal Health
Concentrations and Significant Customer Information
Concentration risk	11.00%		12.00%
Accounts Receivable | Customer Concentration Risk | Two customers
Concentrations and Significant Customer Information
Concentration risk			65.00%
Accounts Receivable | Customer Concentration Risk | Three customers
Concentrations and Significant Customer Information
Concentration risk					73.00%
Feraheme
Concentrations and Significant Customer Information
Number of production facilities			2