Other Balance Sheet Amounts - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued Expenses
Accrued bonuses	$ 13,371	$ 11,402
Accrued commissions	10,616	13,619
Other accrued expenses	23,632	19,090
Total accrued expenses	$ 47,619	$ 44,111