Product Revenue and Concentration of Credit Risks - Revenue Provisions, and Credits or Payments for Sales-related Deductions (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	$ 1,290
Current period provisions	5,253
Payments/credits	(2,616)
Balance at June 30, 2021	3,927
Rebates
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	1,161
Current period provisions	4,073
Payments/credits	(1,521)
Balance at June 30, 2021	3,713
Trade Discounts, Distributor Fees and Other
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	129
Current period provisions	1,180
Payments/credits	(1,095)
Balance at June 30, 2021	$ 214