Basis of Presentation and Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Provision for U.S. product sales allowances and accruals
Gross U.S. product sales	$ 152,192	$ 125,517
Contractual adjustments	45,581	35,134
Government rebates	17,047	12,968
Total provision for U.S product sales allowances and accruals	62,628	48,102
U.S. products sales, net	$ 89,564	$ 77,415