Product Revenue Reserves and Allowances (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 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	66,327	25,329
Adjustments related to prior period sales	670	(293)
Credits and payments made	(54,524)	(18,464)
Ending balance	23,702	10,210
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	21,203	9,750
Adjustments related to prior period sales	(27)	(76)
Credits and payments made	(19,759)	(8,971)
Ending balance	4,615	2,689
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	44,426	15,350
Adjustments related to prior period sales	697	(106)
Credits and payments made	(34,190)	(9,257)
Ending balance	18,553	7,218
Returns
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	411	421
Provision related to sales in the current year	698	229
Adjustments related to prior period sales	0	(111)
Credits and payments made	(575)	(236)
Ending balance	$ 534	$ 303