Summary of Significant Accounting Policies - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]
Balance at beginning	$ 5,635	$ 922
Allowances for current period sales	21,975	15,210
Allowances for prior period sales	(288)	40
Payments and credits	(22,351)	(10,537)
Ending balance	4,971	5,635
Customer Credits, Fees and Discounts
Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]
Balance at beginning	464	234
Allowances for current period sales	3,731	3,151
Allowances for prior period sales	0	14
Payments and credits	(3,742)	(2,935)
Ending balance	453	464
Rebates, Chargebacks and Co-pay Assistance
Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]
Balance at beginning	5,171	688
Allowances for current period sales	18,244	12,059
Allowances for prior period sales	(288)	26
Payments and credits	(18,609)	(7,602)
Ending balance	$ 4,518	$ 5,171