Balance Sheet Components - Accounts Receivable, Net, Prepaid Expenses and Other Current Assets, Inventories, Property and Equipment, Net (Detail) - USD ($) $ in Thousands		Apr. 01, 2016	Dec. 31, 2015
Accounts receivable, net:
Accounts receivable		$ 103,679	$ 73,855
Less: allowances for doubtful accounts, returns and discounts		(8,202)	(4,340)
Total		95,477	69,515
Prepaid expenses and other current assets:
Prepaid inventories to contract manufacturer(1)	[1]	8,500	8,500
Prepaid maintenance, royalty rent and property taxes		8,104	5,974
Other Prepayments		7,616	2,762
Deferred cost of revenue		9,269	4,601
French R&D tax credits receivable(2)	[2]	5,800
Restricted cash(3)	[3]	1,347	1,093
Other		1,682	2,073
Prepaid Expense and Other Assets, Current		42,318	25,003
Inventories:
Raw materials		8,150	5,421
Work-in-process		1,844	1,950
Finished goods		32,421	31,448
Total inventories, net		42,415	38,819
Property and equipment, net:
Furniture and fixtures		8,674	7,808
Machinery and equipment		95,825	93,010
Capitalized software		34,050	29,391
Leasehold improvements		11,724	10,000
Property and equipment, gross		150,273	140,209
Less: accumulated depreciation and amortization		(113,492)	(113,197)
Property and equipment, net		36,781	27,012
Accrued Liabilities, Current [Abstract]
Accrued compensation related expenses and payroll taxes		19,991	10,281
Accrued employee stock plans		3,349	2,680
Accrued TVN contingent consideration (1)	[4]	7,991
Accrued warranty		4,966	3,913
Customer deposit		4,076	953
Others		20,819	13,527
Accrued Liabilities, Current		$ 61,192	$ 31,354

[1] From time to time, the Company makes advance payment to a supplier for future inventory in order to secure more favorable pricing. The Company anticipates that this amount will be offset in the first quarter of 2017 against the accounts payable owed to this supplier.

[2] The Company’s acquired TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche (“CIR”) program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The French R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. TVN French Subsidiary has accumulated approximately $27.6 million of French R&D tax credit receivables at April 1, 2016 for claims from 2012 through 2016. These amounts are subject to audit by the French government and as of April 1, 2016, the 2012 audit for these French R&D credits has been completed and $5.8 million of the French R&D tax credit receivables is expected to be recoverable in 2016. The remaining $21.8 million is expected to be recoverable in 2017 and 2018 and this amount is reported under “Other Long-term Assets” on the Company’s Condensed Consolidated Balance Sheets. Pursuant to the TVN Purchase Agreement, the Company is indemnified by the selling shareholders with respect to the validity and recoverability of the outstanding TVN French Subsidiary R&D tax credit receivables.

[3] The restricted cash balances are primarily held as cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party. Additionally, as of April 1, 2016, the Company recorded approximately $1.1 million of restricted cash for the bank guarantee associated with the TVN French Subsidiary’s office building lease. This amount is reported under “Other Long-term Assets” on the Company’s Condensed Consolidated Balance Sheets.

[4] The TVN acquisition is subject to post-closing adjustments as set forth in the TVN Purchase Agreement to be determined within 90 days from the acquisition date in amounts respectively capped to (i) the difference between €76 million (as converted from euros into U.S. dollars) and $75 million, with respect to an adjustment based on TVN’s 2015 revenue, and (ii) $5 million with respect to an adjustment based on TVN’s 2015 backlog that ships during the first half of 2016.