Product Revenue Reserves and Allowance - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Chargebacks, Discounts, and Fees
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 3,198	$ 1,986
Provision related to sales in the current year	30,960	15,281
Adjustment related to prior periods sales	(81)	(140)
Credits and payments made	(28,338)	(13,929)
Ending balance	5,739	3,198
Government and Other Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	7,620	1,231
Provision related to sales in the current year	62,271	24,156
Adjustment related to prior periods sales	337	254
Credits and payments made	(52,948)	(18,021)
Ending balance	17,280	7,620
Returns
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	411	421
Provision related to sales in the current year	1,673	355
Adjustment related to prior periods sales	(10)	(111)
Credits and payments made	(491)	(254)
Ending balance	1,583	411
Total
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	11,229	3,638
Provision related to sales in the current year	94,904	39,792
Adjustment related to prior periods sales	246	3
Credits and payments made	(81,777)	(32,204)
Ending balance	$ 24,602	$ 11,229