Product Revenue Reserves and Allowances (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Product Revenue Allowance and Reserves
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	$ 11,229	$ 3,638
Provision related to sales in the current year	43,821	14,700
Adjustments related to prior period sales	(340)	(216)
Credits and payments made	(35,929)	(9,726)
Ending balance	18,781	8,396
Chargebacks, Discounts, and Fees
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	3,198	1,986
Provision related to sales in the current year	13,034	5,799
Adjustments related to prior period sales	(16)	55
Credits and payments made	(11,971)	(5,002)
Ending balance	4,245	2,838
Government and other rebates
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	7,620	1,231
Provision related to sales in the current year	30,294	8,680
Adjustments related to prior period sales	(183)	(160)
Credits and payments made	(23,690)	(4,528)
Ending balance	14,041	5,223
Returns
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	411	421
Provision related to sales in the current year	493	221
Adjustments related to prior period sales	(141)	(111)
Credits and payments made	(268)	(196)
Ending balance	$ 495	$ 335