Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue Recognition
Revenue From Royalty Agreement	$ 4,686	$ 3,038	$ 633
Royalty Revenue	4,686	3,038	633
Interest expense	543	1,229	4,963
Revenues	215,003	147,465	92,678
Accrued Sales Deduction	$ 41,943	26,794
Sales return period prior to expiry date	6 months
Sales return period subsequent to expiry date	12 months
Milestone revenues recorded	$ 0	800	2,000
Selling, general and administrative
Advertising Expense
Advertising costs	$ 21,900	19,300	$ 14,800
Sales deductions
Revenue Recognition
Revenues		2,900
Accrued Sales Deduction		$ 26,800