Balance Sheet Components - Balance Sheet Details (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Inventories:
Raw materials	$ 16,698	$ 14,322
Work in process	8,114	7,800
Finished goods	51,418	47,175
Total inventories	76,230	69,297
Prepaid expense
Prepaid commissions	12,385	13,176
Other prepaid expenses	15,390	15,470
Total prepaid expense	27,775	28,646
Property and equipment:
Equipment	66,578	64,384
Furniture and fixtures	6,614	6,517
Leasehold improvements	9,791	9,778
Software	35,915	35,607
Construction in progress	7,625	7,211
Property and equipment, gross	126,523	123,497
Accumulated depreciation and amortization	(85,527)	(81,486)
Total property and equipment, net	40,996	42,011
Other long term assets:
Capitalized software, net	35,391	33,233
Other assets	1,856	1,818
Total other long term assets, net	37,247	35,051
Accrued liabilities:
Advance payments from customers	7,971	7,030
Rebates and lease buyouts	3,905	4,025
Group purchasing organization fees	3,549	3,737
Taxes payable	3,845	4,003
Other accrued liabilities	12,136	12,400
Total accrued liabilities	$ 31,406	$ 31,195