Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Expenses And Other Current Liabilities [Abstract]
Product allowances accruals	$ 37,604	$ 26,995
Accrued inventory	15,324	14,629
Bonus payable	10,730	15,962
Research and development expense accruals	9,092	21,151
Royalties payable	3,707	2,977
Vacation accrual	2,449	2,825
Administrative expenses	2,276	1,805
Sales force commissions and incentive payments payable	1,654	1,933
Commercial and Marketing expense accruals	1,643	2,040
Other accrued expenses	15,649	14,573
Total	$ 100,128	$ 104,890