Accounting Policies - Percentage of Net Product Sales and Accounts Receivable Balance (Details) - Customer Concentration Risk	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Revenue Benchmark
Product Information [Line Items]
Concentration risk percentage	98.00%	98.10%
Revenue Benchmark | Largest Customer
Product Information [Line Items]
Concentration risk percentage	44.50%	42.50%
Revenue Benchmark | Second Largest Customer
Product Information [Line Items]
Concentration risk percentage	32.20%	34.50%
Revenue Benchmark | Third Largest Customer
Product Information [Line Items]
Concentration risk percentage	21.30%	21.10%
Accounts Receivable
Product Information [Line Items]
Concentration risk percentage		99.20%
Accounts Receivable | Largest Customer
Product Information [Line Items]
Concentration risk percentage		56.10%
Accounts Receivable | Second Largest Customer
Product Information [Line Items]
Concentration risk percentage		32.20%
Accounts Receivable | Third Largest Customer
Product Information [Line Items]
Concentration risk percentage		10.90%