Basis of Presentation and Summary of Significant Accounting Policies - Concentration and Significant Customer Information (Details) - facility	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | McKesson Corporation
Concentrations and Significant Customer Information
Concentration risk	40.00%	37.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | AmerisourceBergen Drug Corporation
Concentrations and Significant Customer Information
Concentration risk	31.00%	27.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Cardinal Health
Concentrations and Significant Customer Information
Concentration risk	12.00%	13.00%
Accounts Receivable | Customer Concentration Risk | Three customers
Concentrations and Significant Customer Information
Concentration risk	87.00%		85.00%
Feraheme
Concentrations and Significant Customer Information
Number of production facilities	2