Product Revenue and Concentration of Credit Risks - Revenue Provisions, and Credits or Payments for Sales-related Deductions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	$ 1,290
Current period provisions	2,497
Credits/payments	(1,255)
Balance at March 31, 2021	2,532
Rebates
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	1,161
Current period provisions	1,904
Credits/payments	(774)
Balance at March 31, 2021	2,291
Trade Discounts, Distributor Fees and Other
Sales-related Provisions, Credits and Payments [Roll Forward]
Balance at December 31, 2020	129
Current period provisions	593
Credits/payments	(481)
Balance at March 31, 2021	$ 241