Product Revenue Reserves and Allowances (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Product Revenue Allowance and Reserves
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	$ 3,638	$ 0
Provision related to sales in the current year	16,247	432
Adjustments related to prior period sales	(217)	0
Credits and payments made	(1,552)	0
Ending balance	18,116	432
Chargebacks, Discounts, and Fees
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	1,986	0
Provision related to sales in the current year	8,769	271
Adjustments related to prior period sales	(148)	0
Credits and payments made	(5)	0
Ending balance	10,602	271
Government and other rebates
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	1,231	0
Provision related to sales in the current year	6,961	86
Adjustments related to prior period sales	41	0
Credits and payments made	(1,252)	0
Ending balance	6,981	86
Returns
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	421	0
Provision related to sales in the current year	517	75
Adjustments related to prior period sales	(110)	0
Credits and payments made	(295)	0
Ending balance	$ 533	$ 75