Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Expenses [Abstract]
Accrued sales force commissions and other payments	$ 166,273	$ 167,914
Accrued other taxes	35,922	32,246
Accrued payroll and other employee expenses	24,390	29,220
Accrued payable to vendors	40,914	28,341
Accrued royalties	9,701	10,475
Sales return reserve	7,752	10,118
Deferred revenue	6,644	6,160
Other	19,320	16,373
Total accrued expenses	$ 310,916	$ 300,847