Product Revenue Reserves and Allowance Product Revenue Reserves and Allowance - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Chargebacks, Discounts, and Fees
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 0
Provision related to sales in the current year, net of credits and payments	1,986
Ending balance	1,986
Government and Other Rebates
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	0
Provision related to sales in the current year, net of credits and payments	1,231
Ending balance	1,231
Returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	0
Provision related to sales in the current year, net of credits and payments	421
Ending balance	421
Total
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	0
Provision related to sales in the current year, net of credits and payments	3,638
Ending balance	$ 3,638