Product Revenue Reserves and Allowances (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Product Revenue Allowance and Reserves
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	$ 3,638
Provision related to sales	6,980
Credits and payments made	(1,121)
Ending balance	9,497
Chargebacks, Discounts, and Fees
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	1,986
Provision related to sales	3,580
Credits and payments made	(30)
Ending balance	5,536
Government and other rebates
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	1,231
Provision related to sales	3,196
Credits and payments made	(839)
Ending balance	3,588
Returns
Summary of Activity of Product Revenue Allowance and Reserves
Beginning balance	421
Provision related to sales	204
Credits and payments made	(252)
Ending balance	$ 373