Revenue Recognition - Total Gross Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Provision for product sales allowances and accruals:
Product sales, net	$ 146,254	$ 130,371	$ 263,642	$ 242,912
Product Revenue
Disaggregation of Revenue [Line Items]
Gross product sales	297,732	234,354	537,602	441,078
Provision for product sales allowances and accruals:
Contractual adjustments	111,539	75,684	197,683	145,512
Governmental rebates	39,974	28,328	76,352	52,707
Total	151,513	104,012	274,035	198,219
Product sales, net	$ 146,219	$ 130,342	$ 263,567	$ 242,859