Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts payable	$ 178,183	$ 134,984
Accrued payroll and related costs	191,825	153,086
Accrued clinical trial expense	120,891	91,753
Accrued sales-related charges, deductions and royalties	194,542	159,985
Taxes Payable, Current	227	235,776
Other accrued expenses and liabilities	129,410	103,512
Accounts payable and accrued expenses	$ 815,078	$ 879,096