Balance Sheet Components - Balance Sheet Details (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Inventories:
Raw materials	$ 16,959	$ 14,322
Work in process	7,834	7,800
Finished goods	56,730	47,175
Total inventories	81,523	69,297
Prepaid expense
Prepaid commissions	10,658	13,176
Other prepaid expenses	15,343	15,470
Total prepaid expense	26,001	28,646
Property and equipment:
Equipment	67,561	64,384
Furniture and fixtures	6,666	6,517
Leasehold improvements	9,436	9,778
Software	36,712	35,607
Construction in progress	9,287	7,211
Property and equipment, gross	129,662	123,497
Accumulated depreciation and amortization	(88,949)	(81,486)
Total property and equipment, net	40,713	42,011
Other long term assets:
Capitalized software, net	35,461	33,233
Other assets	1,493	1,818
Total other long term assets, net	36,954	35,051
Accrued liabilities:
Advance payments from customers	8,588	7,030
Rebates and lease buyouts	5,359	4,025
Group purchasing organization fees	3,068	3,737
Taxes payable	3,818	4,003
Other accrued liabilities	10,061	12,400
Total accrued liabilities	$ 30,894	$ 31,195