Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Rebates and other sales deductions	$ 86,495	$ 81,368
Employee compensation and benefits	58,543	54,930
Estimated loss contingency	58,154	0
Inventory-related accruals	8,753	3,002
Accrued interest	7,407	7,297
Selling and marketing accruals	6,780	3,189
Clinical trial accruals	5,904	2,181
Royalties	2,679	8,058
Sales returns reserve	2,510	3,651
Professional fees	2,333	3,213
Derivative instrument liabilities	1,460	5,409
Other	23,869	26,481
Total accrued liabilities	$ 264,887	$ 198,779