Gigamon (GIMO) 10-Q 5 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 27, 2015	Jul. 24, 2015
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 27, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	GIMO
Entity Registrant Name	GIGAMON INC.
Entity Central Index Key	1,484,504
Current Fiscal Year End Date	--12-26
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		33,516,273

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 96,759	$ 38,941
Short-term investments	82,367	110,465
Accounts receivable, net of allowance for doubtful accounts of $17 and $0, as of June 27, 2015 and December 27, 2014, respectively	28,710	28,686
Inventories	4,859	6,551
Deferred tax assets	200	150
Prepaid expenses and other current assets	6,701	5,316
Total current assets	219,596	190,109
Property and equipment, net	7,015	7,387
Deferred tax assets, non-current	76	64
Other assets, non-current	843	426
TOTAL ASSETS	227,530	197,986
CURRENT LIABILITIES:
Accounts payable	2,319	2,391
Accrued liabilities	22,741	22,838
Deferred revenue	51,486	42,183
Total current liabilities	76,546	67,412
Deferred revenue, non-current	17,236	13,322
Deferred tax liability, non-current	200	150
Other liabilities, non-current	1,469	1,667
TOTAL LIABILITIES	$ 95,451	$ 82,551
Commitments and Contingencies
STOCKHOLDERS’ EQUITY
Preferred stock—$0.0001 par value; 20,000 shares authorized, no shares issued or outstanding as of June 27, 2015 and December 27, 2014	$ 0	$ 0
Common stock—$0.0001 par value; 1,000,000 shares authorized, 33,490 and 32,642 shares issued and outstanding as of June 27, 2015 and December 27, 2014, respectively	3	3
Treasury stock— 8,110 shares outstanding as of June 27, 2015 and December 27, 2014	(12,469)	(12,469)
Additional paid-in capital	194,911	177,714
Accumulated other comprehensive income (loss)	10	(94)
Accumulated deficit	(50,376)	(49,719)
TOTAL STOCKHOLDERS’ EQUITY	132,079	115,435
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 227,530	$ 197,986

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 17	$ 0
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	33,489,470	32,641,500
Common stock, shares outstanding	33,489,470	32,641,500
Treasury stock, shares authorized and outstanding	8,109,848	8,109,848

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Revenue:
Product	$ 34,814	$ 22,544	$ 66,966	$ 42,624
Service	16,632	12,307	31,333	23,987
Total revenue	51,446	34,851	98,299	66,611
Cost of revenue:
Product	9,558	6,281	19,003	13,286
Service	1,763	1,544	3,540	3,124
Total cost of revenue	11,321	7,825	22,543	16,410
Gross profit	40,125	27,026	75,756	50,201
Operating expenses:
Research and development	12,227	10,860	23,723	21,798
Sales and marketing	21,171	19,558	40,003	37,728
General and administrative	6,702	4,446	12,721	10,451
Total operating expenses	40,100	34,864	76,447	69,977
Income (loss) from operations	25	(7,838)	(691)	(19,776)
Interest income	105	73	224	134
Other income (expense), net	7	6	(3)	(35)
Income (loss) before income tax provision	137	(7,759)	(470)	(19,677)
Income tax provision	(99)	(24,727)	(187)	(21,027)
Net income (loss)	$ 38	$ (32,486)	$ (657)	$ (40,704)
Net income (loss) per share:
Basic (in dollars per share)	$ 0	$ (1.01)	$ (0.02)	$ (1.28)
Diluted (in dollars per share)	$ 0	$ (1.01)	$ (0.02)	$ (1.28)
Weighted average shares used in computing net income (loss) per share:
Basic (in shares)	33,429	32,116	33,203	31,895
Diluted (in shares)	35,666	32,116	33,203	31,895

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 38	$ (32,486)	$ (657)	$ (40,704)
Other comprehensive (loss) gain:
Other comprehensive (loss) gain:
Change in unrealized (loss) gain on available-for-sale investments	$ (5)	$ 35	$ 104	$ 27
Comprehensive income (loss)	$ 33	$ (32,451)	$ (553)	$ (40,677)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (657)	$ (40,704)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	2,972	2,237
Stock-based compensation expense	15,911	13,897
Deferred income taxes	0	20,877
Inventory write-down	1,012	2,437
Changes in operating assets and liabilities:
Accounts receivable	(24)	7,241
Inventories	310	(7,936)
Prepaid expenses and other assets	(1,802)	(1,097)
Accounts payable	(83)	3,349
Accrued liabilities and other liabilities	(9)	(4,617)
Deferred revenue	13,217	567
Net cash provided by (used in) operating activities	30,847	(3,749)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of short-term investments	(7,999)	(60,644)
Proceeds from sales of short-term investments	1,455	2,000
Proceeds from maturities of short-term investments	34,333	13,412
Purchase of property and equipment	(2,224)	(4,732)
Net cash provided by (used in) investing activities	25,565	(49,964)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from employee stock purchase plan	2,607	3,863
Proceeds from exercise of stock options	2,768	3,571
Costs paid for initial public offering	0	(8)
Shares repurchased for tax withholdings on vesting of restricted stock units	(3,969)	(2,222)
Distribution of income to Gigamon LLC members	0	(476)
Net cash provided by financing activities	1,406	4,728
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	57,818	(48,985)
CASH AND CASH EQUIVALENTS — Beginning of period	38,941	79,908
CASH AND CASH EQUIVALENTS — End of period	96,759	30,923
Unpaid property and equipment purchases	$ 171	$ 860

Description of the Company

Description of the Company	6 Months Ended
	Jun. 27, 2015
Accounting Policies [Abstract]
Description of the Company	Description of the Company The Company Gigamon Inc. (the “Company”) designs, develops and sells products and services that together provide customers with visibility and control of network traffic. The Company serves global enterprises and service providers that seek to maintain and improve the reliability, performance and security of their network infrastructure.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 27, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Consolidation The Company prepared its condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 27, 2014. There have been no changes to the Company’s significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on the Company’s condensed consolidated financial statements and related notes. The Company has a 52- or 53-week fiscal year that ends on the last Saturday in December. Fiscal 2015 is a 52-week fiscal year ending on December 26, 2015 and each quarter therein is a 13-week quarter. Fiscal 2014 was a 52-week fiscal year ending on December 27, 2014 and each quarter therein was a 13-week quarter. Unaudited Interim Financial Statements The accompanying condensed consolidated financial statements are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include normal recurring adjustments, necessary to fairly state the Company’s financial position as of June 27, 2015 , its results of operations, comprehensive income (loss) for the three and six months ended June 27, 2015 and June 28, 2014 , and cash flows for the six months ended June 27, 2015 and June 28, 2014 . The financial data and the other financial information disclosed in the accompanying notes to the condensed consolidated financial statements related to these three and six month periods are also unaudited. The fiscal year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The results of operations in the three and six months ended June 27, 2015 are not necessarily indicative of the results to be expected for the full fiscal year or any other future periods. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reported periods. On an ongoing basis, the Company evaluates its estimates, including but not limited to those related to revenue recognition, provision for doubtful accounts, warranty reserve, excess and obsolete inventory write-downs, stock-based compensation expense, depreciable useful lives and income taxes. The Company bases its estimates on historical experience, projections for future performance and other assumptions that it believes to be reasonable under the circumstances. Actual results could differ materially from those estimates. Cash Equivalents and Marketable Securities All highly liquid marketable securities with original or remaining maturities of less than three months at the date of purchase are considered to be cash equivalents. Marketable securities are generally classified as available-for-sale for use in current operations, if required, and are reported at fair value, with unrealized gains and losses, net of tax, presented as a separate component of stockholders’ equity within accumulated other comprehensive income (loss). All realized gains and losses and unrealized losses resulting from declines in fair value that are other-than-temporary are recorded in other income (expense), net, in the period of occurrence. The Company uses the specific identification method to determine the realized gains and losses on investments. For all investments in marketable securities, the Company assesses whether the impairment is other-than-temporary. If the fair value of a security is less than its amortized cost basis, an impairment is considered other-than-temporary if (i) the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security before recovery of its entire amortized cost basis, or (ii) the Company does not expect to recover the entire amortized cost of the security. If an impairment is considered other-than-temporary based on condition (i), the entire difference between the amortized cost and the fair value of the security is recognized in earnings. If an impairment is considered other-than-temporary based on condition (ii), the amount representing credit losses, defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis of the security, will be recognized in earnings, and the amount relating to all other factors will be recognized in accumulated other comprehensive income (loss). The Company evaluates both qualitative and quantitative factors such as duration and severity of the unrealized losses, credit ratings, default and loss rates of the underlying collateral, structure and credit enhancements to determine if a credit loss may exist. Concentrations The Company operates in highly competitive and rapidly changing markets that could negatively impact the Company’s operating results. A number of components that meet the Company’s manufacturing requirements are available only from single source suppliers. In addition, the Company relies on one contract manufacturer to manufacture substantially all of its products. The inability of its single source suppliers and contract manufacturer to provide the Company with adequate supplies of high-quality components and products could cause a delay in order fulfillment, which could adversely affect the Company’s revenue, cost of revenue and operating results. Financial instruments that potentially subject the Company to significant concentrations of credit risk consist principally of cash, cash equivalents, short-term investments and accounts receivable. The majority of the Company's cash, cash equivalents and short-term investments are held in or managed by a limited number of major financial institutions in the United States that management believes are creditworthy. Such deposits may exceed the insured limits provided on them. The Company mitigates credit risk associated with its accounts receivable by performing ongoing credit evaluations of its customers and determines if it needs to establish an allowance for doubtful accounts for estimated losses based on management’s assessment of the collectability of customer accounts. The Company sells its products primarily through channel partners, including distributors and resellers, and directly to end-user customers. For the three and six months ended June 27, 2015 and June 28, 2014 , no end-user customer accounted for 10% or more of revenue. Customers that represented more than 10% of total revenue or accounts receivable are the following: Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Percent of Revenue: Customer A (distributor) 48 % 43 % 43 % 45 % Customer B (distributor) 18 % 16 % 20 % 15 % As of June 27, 2015 December 27, 2014 Percent of Accounts Receivable: Customer A (distributor) 28 % * Customer B (distributor) 23 % 36 % Customer C (end-user) 15 % * * Represents less than 10% of total accounts receivable Inventories Inventory is valued at the lower of cost computed on a first-in, first-out basis, or market value. The Company writes down inventory in excess of forecasted demand over a certain period, as a component of cost of revenue. In these cases, inventory is reduced to estimated realizable value based on historical usage and expected demand. At the point of inventory write-down, a new lower-cost basis for that inventory is established and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. Inherent in the Company’s estimates of market value in determining inventory valuation are estimates related to economic trends, future demand for the Company’s products, and technical obsolescence of products. The Company uses a contract manufacturer to provide manufacturing services for its products. During the normal course of business, in order to manage manufacturing lead times and help ensure adequate component supply, the Company enters into agreements with the contract manufacturer that either allow them to procure inventory based upon criteria as defined by the Company, or establish the parameters defining the Company’s requirements. A portion of the Company’s reported purchase commitments arising from these agreements consists of non-cancelable commitments. The Company records a liability for firm, non-cancelable and unconditional purchase commitments for quantities in excess of its future demand forecasts consistent with the valuation of the Company’s excess and obsolete inventory. The Company recorded inventory write-downs within cost of revenue of $0.5 million and $0.6 million in the three months ended June 27, 2015 and June 28, 2014 , respectively and $1.0 million and $2.4 million in the six months ended June 27, 2015 and June 28, 2014 , respectively. Revenue Recognition The Company generates product revenue from sales of traffic visibility solutions to customers as well as service revenue from sales of maintenance and support contracts and other billable services. Most of the Company’s products are hardware appliances containing software components that function together to deliver the essential functionality of the solution. The Company typically delivers products and services in a single transaction. The deliverables consist of traffic visibility solutions, maintenance and support, and other billable services. The Company’s typical arrangement includes the sale of one or multiple products that include first year maintenance and support as well as standard warranty. Other arrangements consist of the sale of products bundled with additional maintenance and support or a renewal of maintenance and support contracts. Billable services are billed in advance or when service is provided and performed as requested by customers. Under maintenance and support contracts, services are provided as needed by customers over the fixed arrangement term. The Company does not grant its customers a general right of return or any refund terms, except to two of the Company’s distributors which have a general right of return and in that case, revenue is deferred until sell-through has occurred. Revenue from distributors is reported net of rebates, discounts and any other sales incentives. The Company recognizes revenue when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collectability is reasonably assured. When sales arrangements contain multiple elements and software and non-software components that function together to deliver the products’ essential functionality, the Company allocates revenue to each element based on a selling price hierarchy: vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”) of the selling price if VSOE is not available, or best estimated selling prices (“BESP”) if neither VSOE nor TPE is available. When the Company enters into arrangements to provide more than one product or service (“multiple deliverables”), these arrangements are evaluated to determine if the multiple elements consist of more than one unit of accounting and can be separated accordingly. Based on separation criteria under the guidance, deliverables in multiple element arrangements can be segregated into separate units of accounting if they have value to the customer on a standalone basis. If deliverables can be separated into individual units of accounting, then the arrangement consideration is allocated among deliverables based on their relative selling price. Revenue from each deliverable is recognized when all requirements are met for that specific deliverable. If deliverables cannot be separated into separate units of accounting, then the arrangement will be accounted for as a single unit of accounting and revenue will be recognized when all requirements are met for all deliverables within the arrangement. The Company has established VSOE for maintenance and support contracts since the majority of selling prices fall within a narrow range when sold separately. TPE is not used since this information is not widely available in the market and the Company does not consider its products to be similar to or interchangeable with its competitors’ products in standalone sales to similarly situated customers. For deliverables with no established VSOE, such as standard product offerings, the Company determines the standalone selling price for such deliverables by establishing BESP, which incorporates historical selling prices, the effect of market conditions, gross margin objectives and pricing practices, as well as entity specific factors. The Company monitors and evaluates BESP on a regular basis to ensure that changes in circumstances are accounted for in a timely manner. Service revenue is recognized ratably over the contractual support period, which is typically one year and can be up to five years . In accordance with contractual provisions, the Company may offer cooperative marketing funds based on a fixed dollar percentage of product sales to certain of its channel partners or to fund specific marketing activities for these partners. The Company records such amounts as a reduction to revenue or, if the Company has evidence of fair value of the separable and identifiable benefit received, as a marketing expense. Revenue is recorded net of sales taxes. Costs of products not yet recognized as revenue are deferred and included as a component of prepaid expenses and other current assets in the consolidated balance sheets. As of June 27, 2015 and December 27, 2014 , deferred cost of product revenue was $1.5 million and $0.8 million , respectively. Shipping and Handling Charges Shipping and handling costs are recorded in cost of revenue in the period products are shipped to customers. Warranty The Company provides five -year warranties on its hardware products against defects in manufacturing. The Company accrues for potential liability claims as a component of cost of product revenue based on historical trends of product failure rates and the expected material and labor costs to provide warranty services. The accrued warranty balance is reviewed periodically for adequacy and is included in accrued liabilities and in other non-current liabilities on the consolidated balance sheets. Stock-Based Compensation Stock-based compensation expense related to stock-based transactions, including employee and director awards, as well as employee stock purchase plan purchase rights (“ESPP purchase rights”), is measured and recognized in the consolidated financial statements based on the fair value of the award on the grant date. Stock-based compensation expense related to equity awards that can be settled in cash is measured based on the fair value on each balance sheet date until the settlement dates. The fair value of option awards and ESPP purchase rights is estimated using the Black-Scholes option-pricing model. This model requires assumptions including the market value of the Company’s common stock, expected volatility, expected term of the award, expected dividend yield and risk-free interest rate. Expected term for stock option awards is determined based on the mid-point of the vest period and the contractual period of each option award due to the Company’s limited historical stock option exercise data. Expected volatility is established based on the historical volatility of the common stock of a peer group of publicly traded companies. The stock-based compensation expense, net of estimated forfeitures, is recognized on a graded-vesting basis over the requisite service periods of the awards, unless a performance-based condition exists. Expenses for performance-based awards are recognized when the issuance of the underlying awards are probable. Expenses for consultant awards are measured based on the fair value on the vest date. Expenses related to the option grants to consultants that have not been vested as of the reporting date are marked to market until the earlier of the commitment or the completion of the underlying performance. The Company estimates a forfeiture rate to calculate the stock-based compensation for its awards based on an analysis of its historical experience, analysis of employee turnover and other related factors. The Company is currently using two separate forfeiture rates, based on the classification of the employees. Advertising Costs Expenses related to advertising of products are charged to sales and marketing expense as incurred. For all periods presented, advertising expenses were not material. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our financial statements or tax returns. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized on a more likely than not basis. Significant judgment is required in determining any valuation allowance recorded against deferred tax assets. In assessing the need for a valuation allowance, the Company considers all available evidence, including past operating results, estimates of future taxable income and the feasibility of any viable tax planning strategies. In the event that the Company changes its determination as to the amount of deferred tax assets that can be realized, the Company will adjust its valuation allowance with a corresponding impact to the income tax provision in the period in which such determination is made. Comprehensive Income (Loss) Comprehensive income (loss) is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. Comprehensive income (loss) is comprised of all components of net income (loss) and the changes in the components of accumulated other comprehensive income (loss) within stockholders’ equity. The Company’s accumulated other comprehensive income (loss) includes unrealized gains and losses from its available-for-sale securities that are not considered other-than-temporarily impaired, net of taxes. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (the "FASB") issued an Accounting Standards Update related to revenue from contracts with customers, which supersedes the revenue recognition requirements in the current Accounting Standards Codification. This standard is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. The effective date will be the first quarter of fiscal 2018 using one of two retrospective application methods. The Company is currently evaluating the potential impact, if any, of this accounting standard update on its future consolidated financial statements. In June 2014, the FASB issued an Authoritative standard related to stock compensation Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. This standard requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A company should apply the existing guidance as it relates to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. The amendments in this update are effective for annual periods and interim periods within annual periods beginning after December 15, 2015 and early adoption is permitted. The adoption of this guidance is not currently expected to have a material impact on the Company’s consolidated financial statements. In August 2014, the FASB issued an Authoritative standard related to the disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, to provide guidance on management’s responsibility in evaluating whether there is a substantial doubt about a company’s ability to continue as a going concern and to provide related footnote disclosures. The effective date will be for annual periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not currently expected to have a material impact on the Company’s consolidated financial statements. In June 2015, the FASB issued an Authoritative standard related to Technical Corrections and Improvements. The amendments in this Update cover a wide range of topics in the Codification including guidance clarification and reference corrections, simplification and minor improvements. Transition guidance varies based on the amendments in this Update. The amendments in this Update that require transition guidance are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. All other amendments will be effective upon the issuance of this Update. The Company is currently evaluating the impact, if any, of this guidance on the Company’s consolidated financial statements. In July 2015, the FASB issued an Authoritative standard related to disclosure of Inventory, to provide guidance on management’s responsibility to measure inventory at the lower of cost and net realizable value. The effective date will be for annual periods ending after December 15, 2016 with early adoption permitted. The Company is currently evaluating the impact, if any, of this guidance on the Company’s consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 27, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company records its financial assets and liabilities at fair value. The inputs used in the valuation methodologies in measuring fair value are defined in the fair value hierarchy as follows: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company recognizes transfers among Level 1, Level 2 and Level 3 classifications as of the actual date of the events or change in circumstances that caused the transfers. The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The carrying value of the Company’s accounts receivable, accounts payable and accrued liabilities approximates their fair value due to the short-term nature of these instruments. Cash, Cash Equivalents and Short-Term Investments The Company measures its financial instruments at fair value on a recurring basis. The components of the Company's cash, cash equivalents and short-term investments are as follows (in thousands): Fair Value Measured Using June 27, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 40,896 $ 40,896 $ — $ — Total cash equivalents 40,896 40,896 — — Cash 55,863 Total cash and cash equivalents $ 96,759 Short-term investments: Corporate debt securities $ 30,808 $ — $ 30,808 $ — U.S. agency debt securities 25,550 — 25,550 — U.S. government securities 26,009 — 26,009 — Total short-term investments $ 82,367 $ — $ 82,367 $ — Fair Value Measured Using December 27, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 15,976 $ 15,976 $ — $ — Total cash equivalents 15,976 15,976 — — Cash 22,965 Total cash and cash equivalents $ 38,941 Short-term investments: Corporate debt securities $ 58,707 $ — $ 58,707 $ — U.S. agency debt securities 31,779 — 31,779 — U.S. government securities 19,979 — 19,979 — Total short-term investments $ 110,465 $ — $ 110,465 $ — The Company considers all highly liquid investments with maturity of three months or less at the time of purchase to be cash equivalents. The Company holds money market funds that invest primarily in high-quality short-term money-market instruments, and these funds are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Company presents available-for-sale investments as current assets as they are available for the Company's current operations. Money market funds have been classified as Level 1 because these securities are valued based upon quoted prices in active markets. The Company’s Level 2 assets are priced using quoted market prices for similar instruments or non-binding market prices that are corroborated by observable market data. Observable inputs reflect market data obtained from independent sources. The Company’s policy is to recognize transfers among Level 1, Level 2 and Level 3 classifications as of the actual date of the events or change in circumstances that caused the transfers. The Company did not have any transfers between Level 1 and Level 2 in the six months ended June 27, 2015 . As of June 27, 2015 and December 27, 2014, the Company had no liabilities measured at fair value. Financial instruments measured at amortized costs, gross unrealized gains, gross unrealized losses and fair value by significant investment categories are summarized as follows (in thousands): As of June 27, 2015 Amortized Costs Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Money market funds $ 40,896 $ — $ — $ 40,896 Cash 55,863 — — 55,863 Total cash and cash equivalents $ 96,759 $ — $ — $ 96,759 Short-term investments: Corporate debt securities $ 30,828 $ 1 $ (21 ) $ 30,808 U.S. agency debt securities 25,542 9 (1 ) 25,550 U.S. government securities 25,987 23 (1 ) 26,009 Total short-term investments $ 82,357 $ 33 $ (23 ) $ 82,367 As of December 27, 2014 Amortized Costs Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Money market funds $ 15,976 $ — $ — $ 15,976 Cash 22,965 — — 22,965 Total cash and cash equivalents $ 38,941 $ — $ — $ 38,941 Short-term investments: Corporate debt securities $ 58,777 $ 4 $ (74 ) $ 58,707 U.S. agency debt securities 31,800 1 (22 ) 31,779 U.S. government securities 19,982 7 (10 ) 19,979 Total short-term investments $ 110,559 $ 12 $ (106 ) $ 110,465 The Company’s realized gain was immaterial in the six months ended June 27, 2015 . There were no securities in a continuous loss position for 12 months or longer as of June 27, 2015 or December 27, 2014. The following table summarizes the estimated fair value of the Company’s debt investments, designated as available-for-sale classified by the contractual maturity date of the security (in thousands): As of June 27, 2015 December 27, 2014 Due within one year $ 109,665 $ 90,555 Due between one and five years 13,598 35,886 Total cash equivalents and short-term investments $ 123,263 $ 126,441

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 27, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Inventories Inventories are comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Raw materials $ 183 $ 433 Finished goods 4,676 6,118 Total inventories $ 4,859 $ 6,551 Accrued Liabilities Accrued liabilities are comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Accrued employee related costs $ 14,551 $ 16,021 Accrued inventory and other purchases 1,663 1,830 Accrued professional services 891 761 Other accruals 5,636 4,226 Total accrued liabilities $ 22,741 $ 22,838 Accrued Warranty Accrued Warranty is comprised of (in thousands): Six Months Ended June 27, 2015 June 28, 2014 Accrued warranty balance at beginning of period $ 875 $ 686 Accrual for warranty during the period 593 482 Actual costs incurred (469 ) (456 ) Accrued warranty balance at end of period $ 999 $ 712 Deferred Revenue Deferred revenue is comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Deferred service revenue $ 58,350 $ 51,699 Deferred product revenue 10,372 3,806 Total deferred revenue $ 68,722 $ 55,505 Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) consists of unrealized gains and losses from available-for-sale securities. The following summarizes the activity within accumulated other comprehensive income (loss) (in thousands): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gains (Losses) Balance as of December 27, 2014 $ (94 ) Available-for-sale securities: Unrealized gains, net of taxes 104 Total other comprehensive income 104 Balance as of June 27, 2015 $ 10 There was no tax impact on the unrealized gains or losses and total other comprehensive income. There were no reclassifications out of accumulated other comprehensive income into the consolidated statements of operations in the six months ended June 27, 2015 and the reclassifications for the six months ended June 28, 2014 were immaterial.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 27, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments The Company leases office space for its current headquarters in Santa Clara, California and its United Kingdom subsidiary under non-cancelable operating leases that expire at various times through fiscal 2019. The Company has also entered into lease agreements for additional office space in New York, Virginia, Australia, China (including Hong Kong), Japan, India, Mexico, Russia, Singapore, and the United Arab Emirates. The Company recognizes rent expense on a straight-line basis over the lease period. Rent expense related to the Company’s operating leases was $0.8 million and $0.6 million for the three months ended June 27, 2015 and June 28, 2014 , respectively, and $1.5 million and $1.4 million for the six months ended June 27, 2015 and June 28, 2014 , respectively. Future minimum lease payments under non-cancelable operating leases as of June 27, 2015 were as follows (in thousands): Fiscal Year: 2015 (remaining six months) $ 1,813 2016 3,370 2017 3,333 2018 957 2019 82 Total $ 9,555 Purchase Commitments The Company has agreements with contract manufacturers for the manufacturing of its products. The agreement with its primary contract manufacturer allows the contract manufacturer to procure components on the Company’s behalf based upon a production forecast provided by the Company. The Company may be obligated to purchase component inventory that is non-cancellable. As of June 27, 2015 and December 27, 2014, the Company’s non-cancellable purchase commitments for such component inventory was $3.2 million and $3.5 million , respectively. Legal Proceedings From time to time, the Company may become involved in legal proceedings arising in the ordinary course of business. The Company is not currently a party to any legal proceedings the outcome of which, if determined adversely to the Company, would individually or in the aggregate be expected to have a material adverse effect on its business, operating results, financial condition or cash flows. Indemnification Obligations Under the indemnification provisions of its standard sales related contracts, the Company agrees to defend its customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets, and to pay judgments entered on such claims. The Company’s exposure under these indemnification provisions is generally limited to the total amount paid by its customer under the agreement. However, certain agreements include indemnification provisions that could potentially expose the Company to losses in excess of the amount received under the agreement. The Company has not incurred any costs as a result of such indemnifications and has not accrued any liabilities related to such obligations in its consolidated financial statements. In addition, the Company indemnifies its officers, directors and certain key employees while they are serving in good faith in the company capacities. To date, there have been no claims under any indemnification provisions.

Preferred Stock and Stockholder

Preferred Stock and Stockholders' Equity (Notes)	6 Months Ended
	Jun. 27, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Preferred Stock and Stockholders' Equity	Preferred Stock and Stockholders’ Equity Preferred Stock The Company has authorized 20,000,000 shares of undesignated preferred stock, $0.0001 par value per share. As of June 27, 2015 and December 27, 2014 , the Company had no shares of preferred stock issued or outstanding. Common Stock The Company has authorized 1,000,000,000 shares of common stock, $0.0001 par value per share. Each holder of common stock is entitled to one vote for each share of common stock held. Cumulative voting for the election of directors is not provided in the Company’s amended and restated certificate of incorporation. The Company’s common stock is not entitled to preemptive rights, and is not subject to conversion, redemption or sinking fund provisions. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of common stock are entitled to receive dividends out of funds legally available if the Company's board of directors (the "Board"), in its discretion, determines to issue dividends and then only at the times and in the amounts that the Board may determine. As of June 27, 2015 and December 27, 2014 , the Company had 33,489,470 and 32,641,500 shares of common stock issued and outstanding, respectively. Treasury Stock As of June 27, 2015 and December 27, 2014 , the Company had 8,109,848 shares of treasury stock outstanding, with a carrying value of $12.5 million , or $1.53 per share, within stockholders’ equity on its condensed consolidated balance sheet. The treasury stock was purchased in fiscal 2010 pursuant to a purchase and redemption agreement. Equity Award Plans 2013 Equity Incentive Plan In May 2013, the Company adopted the 2013 Equity Incentive Plan (the “2013 Equity Plan”). All authorized but unissued shares of the Company’s 2012 Unit Option Plan (the "2012 Plan") were added to the 2013 Equity Plan’s authorized pool in June 2013. A maximum of 2,929,481 shares of common stock were initially authorized for future issuance, plus up to an additional 4,967,172 shares upon termination of awards under the 2012 Plan. In addition, the 2013 Equity Plan is subject to an annual increase on the first day of each of the Company’s fiscal years, by an amount equal to the least of (i) 1,464,740 shares, (ii) 5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year, or (iii) such other amount as determined by the Board. In the twelve months ended December 27, 2014, an additional 1,464,740 shares of common stock were authorized for future issuance under the 2013 Equity Plan and an additional 1,464,740 shares were authorized during the six months ended June 27, 2015 . Vested but unexercised options, under the 2013 Equity Plan, expire three months after termination of service with the Company. As of June 27, 2015 , outstanding awards under the 2013 Equity Plan and the 2012 Plan covered 3,206,027 shares and 1,351,190 shares of the Company's common stock, respectively. The 2013 Equity Plan permits the grant of stock options, stock appreciation rights, restricted stock, restricted stock units ("RSUs"), performance units and performance shares to employees, directors and consultants of the Company. Employee Stock Purchase Plan In conjunction with the completion of its initial public offering (the "IPO") in June 2013, the Company adopted the 2013 Employee Stock Purchase Plan (the “ESPP”). A maximum of 439,422 shares were initially authorized for future issuance. In addition, the ESPP is subject to an annual increase on the first day of each of the Company's fiscal years, by an amount equal to the least of (i) 439,422 shares, (ii) 1.5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year, or (iii) such other amount as determined by the Board. In the twelve months ended December 27, 2014, an additional 439,422 shares of common stock were authorized for future issuance under the ESPP and an additional 439,422 shares were authorized during the six months ended June 27, 2015 . Eligible employees can purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to plan limitations. Employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock (i) at the date of commencement of the offering period or (ii) at the last day of the purchase period. The ESPP provides for a 24 -month offering period comprised of four purchase periods of approximately six months . The offering periods are scheduled to start on the first trading day on or after February 15 and August 15 of each year, except for the first offering period, which commenced on the first trading day upon the completion of the Company’s IPO, or June 12, 2013, and ends on August 17, 2015. The Company recorded stock-based compensation expense for its ESPP of $0.7 million and $1.4 million for the three and six months ended June 27, 2015 , respectively, and $1.1 million and $2.8 million for the three and six months ended June 28, 2014 , respectively. For the six months ended June 27, 2015 there was one purchase period that resulted in the issuance of 273,301 shares of common stock at a weighted average purchase price of $9.54 per share. Stock Option Stock options granted under the 2013 Equity Plan and formerly under the 2012 Plan (together, the “Option Plans”), are generally subject to a four -year vesting period whereby stock options become 25% vested on the first anniversary of the grant date and then ratably monthly thereafter through the end of the vesting period. Vested stock options may be exercised up to ten years from the vesting commencement date, with certain options granted in fiscal 2015 expiring seven years from the date of grant. Under the 2012 Plan, vested but unexercised stock options expire 30 days after termination of service with the Company. Under the 2013 Equity Plan, vested but unexercised stock options expire three months after termination of service with the Company. The following table summarizes the stock option activity under the Company’s Option Plans: Number of Weighted- Weighted- Aggregate (in thousands) Balance — December 27, 2014 2,386,412 $ 12.91 8.21 $ 14,403 Options granted 408,000 $ 21.44 Options exercised (340,889 ) $ 8.08 Options canceled (78,210 ) $ 10.08 Balance — June 27, 2015 2,375,313 $ 15.16 7.50 $ 44,291 Vested and expected to vest — June 27, 2015 2,212,151 $ 14.90 7.50 $ 41,846 Exercisable — June 27, 2015 985,259 $ 12.40 7.28 $ 21,104 Aggregate intrinsic value represents the difference between the exercise price of the awards and the Company’s fair value per share of $33.82 and $17.47 as of June 27, 2015 and December 27, 2014 , respectively, for the total number of underlying options. Weighted-average fair value per share for option awards vested in the six months ended June 27, 2015 and June 28, 2014 was $10.18 and $ 9.18 , respectively. As of June 27, 2015 and December 27, 2014, there were 31,766 and 36,495 shares of common stock subject to stock options with performance-based vesting criteria, respectively. Restricted Stock Unit Activity RSUs generally vest over a period of one to four years. RSU vesting dates are determined by the Company. The vesting is subject to the employee’s continuing service with the Company over that period. Until vested, RSUs do not have the voting or dividend participation rights of the Company’s common stock and the shares of the Company’s common stock underlying the awards are not considered issued and outstanding. The cost of RSUs is determined using the fair value of the Company’s common stock on the date of the grant. The following table summarizes the RSU activity under the Company’s Option Plans: Number of Weighted- Weighted- Aggregate (in thousands) Balance - December 27, 2014 1,733,225 $ 18.78 1.27 $ 30,279 RSUs granted 1,019,205 $ 22.73 RSUs vested (381,419 ) $ 19.09 RSUs canceled (187,552 ) $ 22.31 Balance - June 27, 2015 2,183,459 $ 20.27 1.40 $ 73,845 Vested and expected to vest — June 27, 2015 1,896,384 $ 20.09 1.28 $ 64,136 Aggregate intrinsic value for RSUs represents the Company’s fair market value per share of $33.82 and $17.47 , as of June 27, 2015 and December 27, 2014, respectively, for the total number of underlying RSUs. Stock-Based Compensation Expense The fair value of stock options and ESPP purchase rights is estimated on the date of grant using the Black-Scholes option-pricing model. The fair values of the option awards and ESPP purchase rights granted and the assumptions used in the Black-Scholes option pricing model are summarized as follows: Three Months Ended Six Months Ended June 27, June 28, June 27, June 28, Stock option awards: Expected term (in years) — 5.3-6.1 4.6 5.3-6.1 Risk-free interest rate — 1.7%-1.8% 1.6% 1.7%-1.9% Expected volatility — 59.4% 56.04% 59.4%-61.9% Expected dividend rate —% —% —% —% Grant date fair value per award — $9.20 - $9.86 $10.11 $9.20 - $17.67 ESPP purchase right: Expected term (in years) 0.50 - 2.0 0.50 - 2.0 0.50 - 2.0 0.50 - 2.0 Risk-free interest rate 0.07% - 0.70% 0.1% - 0.3% 0.07% - 0.70% 0.1% - 0.3% Expected volatility 37.6% - 50.3% 44.8% - 52.7% 37.6% - 50.3% 44.8% - 52.7% Expected dividend rate —% —% —% —% Grant date fair value per share $5.48 - $9.18 $8.23 - $13.06 $5.48 - $9.18 $8.23 - $13.06 The following table summarizes the stock-based compensation expense recorded in the Company’s condensed consolidated statement of operations (in thousands): Three Months Ended Six Months Ended June 27, June 28, June 27, June 28, Cost of revenue $ 510 $ 471 $ 1,059 $ 919 Research and development $ 2,609 2,054 4,705 4,653 Sales and marketing $ 2,812 2,424 5,260 5,198 General and administrative $ 2,655 1,090 4,905 3,127 Total stock-based compensation expense $ 8,586 $ 6,039 $ 15,929 $ 13,897 As of June 27, 2015 , unrecognized compensation expense related to stock options, RSUs and ESPP purchase rights, net of estimated forfeitures, was $5.6 million , $21.8 million and $1.7 million , respectively.

Defined Contribution Plans

Defined Contribution Plans	6 Months Ended
	Jun. 27, 2015
Postemployment Benefits [Abstract]
Defined Contribution Plans	Defined Contribution Plans The Company’s contributions to the 401(k) defined contribution plan, which are expensed immediately as compensation costs, were $0.4 million and $0.6 million for the three months ended June 27, 2015 and June 28, 2014 , respectively, and $0.8 million and $1.2 million for the six months ended June 27, 2015 and June 28, 2014 , respectively.

Income Tax

Income Tax	6 Months Ended
	Jun. 27, 2015
Income Tax Disclosure [Abstract]
Income Tax	Income Tax The Company recorded an income tax provision of $0.1 million and $0.2 million for the three and six months ended June 27, 2015 , respectively, and $24.7 million and $21.0 million for the three and six months ended June 28, 2014 , respectively. The income tax provision for the three and six months ended June 27, 2015 represents foreign income tax expense. The income tax provision recorded does not reflect any projected change in net deferred taxes, as the Company cannot conclude that it is more likely than not that it will be able to utilize its deferred tax assets in the foreseeable future. The Company's income tax provision for the three and six months ended June 28, 2014 was primarily related to the establishment of a valuation allowance against the deferred tax assets in the United States and the taxes assessed by foreign jurisdictions. As of June 28, 2014, the Company assessed that it was more-likely-than-not that it will not realize its federal and state deferred tax assets based on the absence of sufficient positive objective evidence that it would generate sufficient taxable income in our U.S. tax jurisdiction to realize the deferred tax assets. Accordingly, the Company recorded a valuation allowance of $24.6 million on its federal and state deferred tax assets which resulted in an increase to its income tax provision. The Company files annual income tax returns in multiple tax jurisdictions on a worldwide basis. A number of years may lapse before an uncertain tax position is audited and finally resolved. While it is often difficult to predict the final outcome or the timing of resolution of any particular uncertain tax position, the Company believes that its reserves for income taxes reflect the most likely outcomes. The Company adjusts these reserves, as well as the related interest, in light of changing facts and circumstances. Settlement of any particular position could require the use of cash. As of June 27, 2015 , changes to the Company's uncertain tax positions in the next 12 months that are reasonably possible are not expected to have a material impact on the Company's financial position or results of operations. The Company recognizes interest and penalties related to uncertain tax positions as part of the income tax provision. To date, no such interest and penalties have been accrued.

Net Income (Loss) Net Income (L

Net Income (Loss) Net Income (Loss)	6 Months Ended
	Jun. 27, 2015
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Net Income (Loss) per Share Basic net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding. Due to the net loss incurred in the three months ended June 28, 2014 and the six months ended June 27, 2015 and June 28, 2014 , potential dilutive securities were excluded from the calculation of diluted net loss per share attributable to common stockholders for such period as their effect was anti-dilutive. The following table presents the computation of basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except per share data): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Numerator: Net income (loss) attributable to common stockholders $ 38 $ (32,486 ) $ (657 ) $ (40,704 ) Denominator: Weighted average shares used for basic net income (loss) per share computation 33,429 32,116 33,203 31,895 Weighted average effect of dilutive securities: Stock options 1,079 — — — RSUs 738 — — — ESPP purchase rights 420 — — — Weighted average shares used for diluted net income (loss) per share computation 35,666 32,116 33,203 31,895 Net income (loss) per share attributable to common stockholders : Basic $ — $ (1.01 ) $ (0.02 ) $ (1.28 ) Diluted $ — $ (1.01 ) $ (0.02 ) $ (1.28 ) The weighted average number of shares outstanding used in the computation of diluted net income (loss) per share does not include the effect of the following shares of potentially outstanding common stock because the effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Equity awards to purchase common stock 1,058 4,358 4,771 4,520

Segment Information

Segment Information	6 Months Ended
	Jun. 27, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information Operating segments are defined as components of an enterprise that engage in business activities for which separate discrete financial information is available and evaluated by the chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its chief executive officer. The chief executive officer reviews financial information presented on a consolidated basis, for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, or plans for levels or components below the consolidated unit level. Accordingly, the Company operates as a single reportable segment. The following table summarizes the Company’s revenue by geographic region, based on the location to where the product was shipped (in thousands): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 United States $ 37,798 $ 25,152 $ 70,431 $ 49,573 Rest of Americas 2,957 2,321 6,048 4,018 Europe, Middle East and Africa 6,780 4,826 14,262 8,530 Asia Pacific 3,911 2,552 7,558 4,490 Total $ 51,446 $ 34,851 $ 98,299 $ 66,611 The Company’s long-lived assets by geographic region are summarized as follows (in thousands): As of June 27, 2015 December 27, 2014 United States $ 6,800 $ 7,218 Other 215 169 Total $ 7,015 $ 7,387

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 27, 2015
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and Consolidation The Company prepared its condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 27, 2014. There have been no changes to the Company’s significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on the Company’s condensed consolidated financial statements and related notes.
Fiscal Period Policy	The Company has a 52- or 53-week fiscal year that ends on the last Saturday in December. Fiscal 2015 is a 52-week fiscal year ending on December 26, 2015 and each quarter therein is a 13-week quarter. Fiscal 2014 was a 52-week fiscal year ending on December 27, 2014 and each quarter therein was a 13-week quarter.
Unaudited Interim Disclosure Policy [Text Block]	Unaudited Interim Financial Statements The accompanying condensed consolidated financial statements are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include normal recurring adjustments, necessary to fairly state the Company’s financial position as of June 27, 2015 , its results of operations, comprehensive income (loss) for the three and six months ended June 27, 2015 and June 28, 2014 , and cash flows for the six months ended June 27, 2015 and June 28, 2014 . The financial data and the other financial information disclosed in the accompanying notes to the condensed consolidated financial statements related to these three and six month periods are also unaudited. The fiscal year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The results of operations in the three and six months ended June 27, 2015 are not necessarily indicative of the results to be expected for the full fiscal year or any other future periods.
Basis of Presentation and Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reported periods. On an ongoing basis, the Company evaluates its estimates, including but not limited to those related to revenue recognition, provision for doubtful accounts, warranty reserve, excess and obsolete inventory write-downs, stock-based compensation expense, depreciable useful lives and income taxes. The Company bases its estimates on historical experience, projections for future performance and other assumptions that it believes to be reasonable under the circumstances. Actual results could differ materially from those estimates.
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities All highly liquid marketable securities with original or remaining maturities of less than three months at the date of purchase are considered to be cash equivalents. Marketable securities are generally classified as available-for-sale for use in current operations, if required, and are reported at fair value, with unrealized gains and losses, net of tax, presented as a separate component of stockholders’ equity within accumulated other comprehensive income (loss). All realized gains and losses and unrealized losses resulting from declines in fair value that are other-than-temporary are recorded in other income (expense), net, in the period of occurrence. The Company uses the specific identification method to determine the realized gains and losses on investments. For all investments in marketable securities, the Company assesses whether the impairment is other-than-temporary. If the fair value of a security is less than its amortized cost basis, an impairment is considered other-than-temporary if (i) the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security before recovery of its entire amortized cost basis, or (ii) the Company does not expect to recover the entire amortized cost of the security. If an impairment is considered other-than-temporary based on condition (i), the entire difference between the amortized cost and the fair value of the security is recognized in earnings. If an impairment is considered other-than-temporary based on condition (ii), the amount representing credit losses, defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis of the security, will be recognized in earnings, and the amount relating to all other factors will be recognized in accumulated other comprehensive income (loss). The Company evaluates both qualitative and quantitative factors such as duration and severity of the unrealized losses, credit ratings, default and loss rates of the underlying collateral, structure and credit enhancements to determine if a credit loss may exist.
Concentrations	Concentrations The Company operates in highly competitive and rapidly changing markets that could negatively impact the Company’s operating results. A number of components that meet the Company’s manufacturing requirements are available only from single source suppliers. In addition, the Company relies on one contract manufacturer to manufacture substantially all of its products. The inability of its single source suppliers and contract manufacturer to provide the Company with adequate supplies of high-quality components and products could cause a delay in order fulfillment, which could adversely affect the Company’s revenue, cost of revenue and operating results. Financial instruments that potentially subject the Company to significant concentrations of credit risk consist principally of cash, cash equivalents, short-term investments and accounts receivable. The majority of the Company's cash, cash equivalents and short-term investments are held in or managed by a limited number of major financial institutions in the United States that management believes are creditworthy. Such deposits may exceed the insured limits provided on them. The Company mitigates credit risk associated with its accounts receivable by performing ongoing credit evaluations of its customers and determines if it needs to establish an allowance for doubtful accounts for estimated losses based on management’s assessment of the collectability of customer accounts. The Company sells its products primarily through channel partners, including distributors and resellers, and directly to end-user customers. For the three and six months ended June 27, 2015 and June 28, 2014 , no end-user customer accounted for 10% or more of revenue.
Inventories	Inventories Inventory is valued at the lower of cost computed on a first-in, first-out basis, or market value. The Company writes down inventory in excess of forecasted demand over a certain period, as a component of cost of revenue. In these cases, inventory is reduced to estimated realizable value based on historical usage and expected demand. At the point of inventory write-down, a new lower-cost basis for that inventory is established and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. Inherent in the Company’s estimates of market value in determining inventory valuation are estimates related to economic trends, future demand for the Company’s products, and technical obsolescence of products. The Company uses a contract manufacturer to provide manufacturing services for its products. During the normal course of business, in order to manage manufacturing lead times and help ensure adequate component supply, the Company enters into agreements with the contract manufacturer that either allow them to procure inventory based upon criteria as defined by the Company, or establish the parameters defining the Company’s requirements. A portion of the Company’s reported purchase commitments arising from these agreements consists of non-cancelable commitments. The Company records a liability for firm, non-cancelable and unconditional purchase commitments for quantities in excess of its future demand forecasts consistent with the valuation of the Company’s excess and obsolete inventory.
Revenue Recognition	Revenue Recognition The Company generates product revenue from sales of traffic visibility solutions to customers as well as service revenue from sales of maintenance and support contracts and other billable services. Most of the Company’s products are hardware appliances containing software components that function together to deliver the essential functionality of the solution. The Company typically delivers products and services in a single transaction. The deliverables consist of traffic visibility solutions, maintenance and support, and other billable services. The Company’s typical arrangement includes the sale of one or multiple products that include first year maintenance and support as well as standard warranty. Other arrangements consist of the sale of products bundled with additional maintenance and support or a renewal of maintenance and support contracts. Billable services are billed in advance or when service is provided and performed as requested by customers. Under maintenance and support contracts, services are provided as needed by customers over the fixed arrangement term. The Company does not grant its customers a general right of return or any refund terms, except to two of the Company’s distributors which have a general right of return and in that case, revenue is deferred until sell-through has occurred. Revenue from distributors is reported net of rebates, discounts and any other sales incentives. The Company recognizes revenue when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collectability is reasonably assured. When sales arrangements contain multiple elements and software and non-software components that function together to deliver the products’ essential functionality, the Company allocates revenue to each element based on a selling price hierarchy: vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”) of the selling price if VSOE is not available, or best estimated selling prices (“BESP”) if neither VSOE nor TPE is available. When the Company enters into arrangements to provide more than one product or service (“multiple deliverables”), these arrangements are evaluated to determine if the multiple elements consist of more than one unit of accounting and can be separated accordingly. Based on separation criteria under the guidance, deliverables in multiple element arrangements can be segregated into separate units of accounting if they have value to the customer on a standalone basis. If deliverables can be separated into individual units of accounting, then the arrangement consideration is allocated among deliverables based on their relative selling price. Revenue from each deliverable is recognized when all requirements are met for that specific deliverable. If deliverables cannot be separated into separate units of accounting, then the arrangement will be accounted for as a single unit of accounting and revenue will be recognized when all requirements are met for all deliverables within the arrangement. The Company has established VSOE for maintenance and support contracts since the majority of selling prices fall within a narrow range when sold separately. TPE is not used since this information is not widely available in the market and the Company does not consider its products to be similar to or interchangeable with its competitors’ products in standalone sales to similarly situated customers. For deliverables with no established VSOE, such as standard product offerings, the Company determines the standalone selling price for such deliverables by establishing BESP, which incorporates historical selling prices, the effect of market conditions, gross margin objectives and pricing practices, as well as entity specific factors. The Company monitors and evaluates BESP on a regular basis to ensure that changes in circumstances are accounted for in a timely manner. Service revenue is recognized ratably over the contractual support period, which is typically one year and can be up to five years . In accordance with contractual provisions, the Company may offer cooperative marketing funds based on a fixed dollar percentage of product sales to certain of its channel partners or to fund specific marketing activities for these partners. The Company records such amounts as a reduction to revenue or, if the Company has evidence of fair value of the separable and identifiable benefit received, as a marketing expense. Revenue is recorded net of sales taxes. Costs of products not yet recognized as revenue are deferred and included as a component of prepaid expenses and other current assets in the consolidated balance sheets.
Shipping and Handling Charges	Shipping and Handling Charges Shipping and handling costs are recorded in cost of revenue in the period products are shipped to customers.
Warranty	Warranty The Company provides five -year warranties on its hardware products against defects in manufacturing. The Company accrues for potential liability claims as a component of cost of product revenue based on historical trends of product failure rates and the expected material and labor costs to provide warranty services. The accrued warranty balance is reviewed periodically for adequacy and is included in accrued liabilities and in other non-current liabilities on the consolidated balance sheets.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense related to stock-based transactions, including employee and director awards, as well as employee stock purchase plan purchase rights (“ESPP purchase rights”), is measured and recognized in the consolidated financial statements based on the fair value of the award on the grant date. Stock-based compensation expense related to equity awards that can be settled in cash is measured based on the fair value on each balance sheet date until the settlement dates. The fair value of option awards and ESPP purchase rights is estimated using the Black-Scholes option-pricing model. This model requires assumptions including the market value of the Company’s common stock, expected volatility, expected term of the award, expected dividend yield and risk-free interest rate. Expected term for stock option awards is determined based on the mid-point of the vest period and the contractual period of each option award due to the Company’s limited historical stock option exercise data. Expected volatility is established based on the historical volatility of the common stock of a peer group of publicly traded companies. The stock-based compensation expense, net of estimated forfeitures, is recognized on a graded-vesting basis over the requisite service periods of the awards, unless a performance-based condition exists. Expenses for performance-based awards are recognized when the issuance of the underlying awards are probable. Expenses for consultant awards are measured based on the fair value on the vest date. Expenses related to the option grants to consultants that have not been vested as of the reporting date are marked to market until the earlier of the commitment or the completion of the underlying performance. The Company estimates a forfeiture rate to calculate the stock-based compensation for its awards based on an analysis of its historical experience, analysis of employee turnover and other related factors.
Advertising Costs	Advertising Costs Expenses related to advertising of products are charged to sales and marketing expense as incurred. For all periods presented, advertising expenses were not material.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our financial statements or tax returns. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized on a more likely than not basis. Significant judgment is required in determining any valuation allowance recorded against deferred tax assets. In assessing the need for a valuation allowance, the Company considers all available evidence, including past operating results, estimates of future taxable income and the feasibility of any viable tax planning strategies. In the event that the Company changes its determination as to the amount of deferred tax assets that can be realized, the Company will adjust its valuation allowance with a corresponding impact to the income tax provision in the period in which such determination is made.
Comprehensive Loss	Comprehensive Income (Loss) Comprehensive income (loss) is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. Comprehensive income (loss) is comprised of all components of net income (loss) and the changes in the components of accumulated other comprehensive income (loss) within stockholders’ equity. The Company’s accumulated other comprehensive income (loss) includes unrealized gains and losses from its available-for-sale securities that are not considered other-than-temporarily impaired, net of taxes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (the "FASB") issued an Accounting Standards Update related to revenue from contracts with customers, which supersedes the revenue recognition requirements in the current Accounting Standards Codification. This standard is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. The effective date will be the first quarter of fiscal 2018 using one of two retrospective application methods. The Company is currently evaluating the potential impact, if any, of this accounting standard update on its future consolidated financial statements. In June 2014, the FASB issued an Authoritative standard related to stock compensation Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. This standard requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A company should apply the existing guidance as it relates to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. The amendments in this update are effective for annual periods and interim periods within annual periods beginning after December 15, 2015 and early adoption is permitted. The adoption of this guidance is not currently expected to have a material impact on the Company’s consolidated financial statements. In August 2014, the FASB issued an Authoritative standard related to the disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, to provide guidance on management’s responsibility in evaluating whether there is a substantial doubt about a company’s ability to continue as a going concern and to provide related footnote disclosures. The effective date will be for annual periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not currently expected to have a material impact on the Company’s consolidated financial statements. In June 2015, the FASB issued an Authoritative standard related to Technical Corrections and Improvements. The amendments in this Update cover a wide range of topics in the Codification including guidance clarification and reference corrections, simplification and minor improvements. Transition guidance varies based on the amendments in this Update. The amendments in this Update that require transition guidance are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. All other amendments will be effective upon the issuance of this Update. The Company is currently evaluating the impact, if any, of this guidance on the Company’s consolidated financial statements. In July 2015, the FASB issued an Authoritative standard related to disclosure of Inventory, to provide guidance on management’s responsibility to measure inventory at the lower of cost and net realizable value. The effective date will be for annual periods ending after December 15, 2016 with early adoption permitted. The Company is currently evaluating the impact, if any, of this guidance on the Company’s consolidated financial statements.

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 27, 2015
Accounting Policies [Abstract]
Customers Representing Major Revenue and Accounts Receivable	Customers that represented more than 10% of total revenue or accounts receivable are the following: Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Percent of Revenue: Customer A (distributor) 48 % 43 % 43 % 45 % Customer B (distributor) 18 % 16 % 20 % 15 % As of June 27, 2015 December 27, 2014 Percent of Accounts Receivable: Customer A (distributor) 28 % * Customer B (distributor) 23 % 36 % Customer C (end-user) 15 % * * Represents less than 10% of total accounts receivable

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 27, 2015
Fair Value Disclosures [Abstract]
Components of Cash and Cash Equivalents	The Company measures its financial instruments at fair value on a recurring basis. The components of the Company's cash, cash equivalents and short-term investments are as follows (in thousands): Fair Value Measured Using June 27, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 40,896 $ 40,896 $ — $ — Total cash equivalents 40,896 40,896 — — Cash 55,863 Total cash and cash equivalents $ 96,759 Short-term investments: Corporate debt securities $ 30,808 $ — $ 30,808 $ — U.S. agency debt securities 25,550 — 25,550 — U.S. government securities 26,009 — 26,009 — Total short-term investments $ 82,367 $ — $ 82,367 $ — Fair Value Measured Using December 27, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 15,976 $ 15,976 $ — $ — Total cash equivalents 15,976 15,976 — — Cash 22,965 Total cash and cash equivalents $ 38,941 Short-term investments: Corporate debt securities $ 58,707 $ — $ 58,707 $ — U.S. agency debt securities 31,779 — 31,779 — U.S. government securities 19,979 — 19,979 — Total short-term investments $ 110,465 $ — $ 110,465 $ —
Schedule of Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Investments	Financial instruments measured at amortized costs, gross unrealized gains, gross unrealized losses and fair value by significant investment categories are summarized as follows (in thousands): As of June 27, 2015 Amortized Costs Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Money market funds $ 40,896 $ — $ — $ 40,896 Cash 55,863 — — 55,863 Total cash and cash equivalents $ 96,759 $ — $ — $ 96,759 Short-term investments: Corporate debt securities $ 30,828 $ 1 $ (21 ) $ 30,808 U.S. agency debt securities 25,542 9 (1 ) 25,550 U.S. government securities 25,987 23 (1 ) 26,009 Total short-term investments $ 82,357 $ 33 $ (23 ) $ 82,367 As of December 27, 2014 Amortized Costs Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Money market funds $ 15,976 $ — $ — $ 15,976 Cash 22,965 — — 22,965 Total cash and cash equivalents $ 38,941 $ — $ — $ 38,941 Short-term investments: Corporate debt securities $ 58,777 $ 4 $ (74 ) $ 58,707 U.S. agency debt securities 31,800 1 (22 ) 31,779 U.S. government securities 19,982 7 (10 ) 19,979 Total short-term investments $ 110,559 $ 12 $ (106 ) $ 110,465
Schedule of Contractual Maturity Date of Marketable Securities	As of June 27, 2015 December 27, 2014 Due within one year $ 109,665 $ 90,555 Due between one and five years 13,598 35,886 Total cash equivalents and short-term investments $ 123,263 $ 126,441

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 27, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventories	Inventories are comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Raw materials $ 183 $ 433 Finished goods 4,676 6,118 Total inventories $ 4,859 $ 6,551
Accrued Liabilities	Accrued liabilities are comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Accrued employee related costs $ 14,551 $ 16,021 Accrued inventory and other purchases 1,663 1,830 Accrued professional services 891 761 Other accruals 5,636 4,226 Total accrued liabilities $ 22,741 $ 22,838
Accrued Warranty Liability	Accrued Warranty is comprised of (in thousands): Six Months Ended June 27, 2015 June 28, 2014 Accrued warranty balance at beginning of period $ 875 $ 686 Accrual for warranty during the period 593 482 Actual costs incurred (469 ) (456 ) Accrued warranty balance at end of period $ 999 $ 712
Deferred Revenue	Deferred revenue is comprised of the following (in thousands): As of June 27, 2015 December 27, 2014 Deferred service revenue $ 58,350 $ 51,699 Deferred product revenue 10,372 3,806 Total deferred revenue $ 68,722 $ 55,505
Accumulated Other Comprehensive Income	The following summarizes the activity within accumulated other comprehensive income (loss) (in thousands): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gains (Losses) Balance as of December 27, 2014 $ (94 ) Available-for-sale securities: Unrealized gains, net of taxes 104 Total other comprehensive income 104 Balance as of June 27, 2015 $ 10

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 27, 2015
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments Under Non-Cancelable Operating Leases	Future minimum lease payments under non-cancelable operating leases as of June 27, 2015 were as follows (in thousands): Fiscal Year: 2015 (remaining six months) $ 1,813 2016 3,370 2017 3,333 2018 957 2019 82 Total $ 9,555

Preferred Stock and Stockhold22

Preferred Stock and Stockholders' Equity (Tables)	6 Months Ended
	Jun. 27, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock Options Activity	The following table summarizes the stock option activity under the Company’s Option Plans: Number of Weighted- Weighted- Aggregate (in thousands) Balance — December 27, 2014 2,386,412 $ 12.91 8.21 $ 14,403 Options granted 408,000 $ 21.44 Options exercised (340,889 ) $ 8.08 Options canceled (78,210 ) $ 10.08 Balance — June 27, 2015 2,375,313 $ 15.16 7.50 $ 44,291 Vested and expected to vest — June 27, 2015 2,212,151 $ 14.90 7.50 $ 41,846 Exercisable — June 27, 2015 985,259 $ 12.40 7.28 $ 21,104
Schedule of RSU Activity	The following table summarizes the RSU activity under the Company’s Option Plans: Number of Weighted- Weighted- Aggregate (in thousands) Balance - December 27, 2014 1,733,225 $ 18.78 1.27 $ 30,279 RSUs granted 1,019,205 $ 22.73 RSUs vested (381,419 ) $ 19.09 RSUs canceled (187,552 ) $ 22.31 Balance - June 27, 2015 2,183,459 $ 20.27 1.40 $ 73,845 Vested and expected to vest — June 27, 2015 1,896,384 $ 20.09 1.28 $ 64,136
Schedule of Fair Values of the Options Awards and ESPP Purchase Rights Granted	The fair values of the option awards and ESPP purchase rights granted and the assumptions used in the Black-Scholes option pricing model are summarized as follows: Three Months Ended Six Months Ended June 27, June 28, June 27, June 28, Stock option awards: Expected term (in years) — 5.3-6.1 4.6 5.3-6.1 Risk-free interest rate — 1.7%-1.8% 1.6% 1.7%-1.9% Expected volatility — 59.4% 56.04% 59.4%-61.9% Expected dividend rate —% —% —% —% Grant date fair value per award — $9.20 - $9.86 $10.11 $9.20 - $17.67 ESPP purchase right: Expected term (in years) 0.50 - 2.0 0.50 - 2.0 0.50 - 2.0 0.50 - 2.0 Risk-free interest rate 0.07% - 0.70% 0.1% - 0.3% 0.07% - 0.70% 0.1% - 0.3% Expected volatility 37.6% - 50.3% 44.8% - 52.7% 37.6% - 50.3% 44.8% - 52.7% Expected dividend rate —% —% —% —% Grant date fair value per share $5.48 - $9.18 $8.23 - $13.06 $5.48 - $9.18 $8.23 - $13.06
Summary of Stock-based Compensation Expense	The following table summarizes the stock-based compensation expense recorded in the Company’s condensed consolidated statement of operations (in thousands): Three Months Ended Six Months Ended June 27, June 28, June 27, June 28, Cost of revenue $ 510 $ 471 $ 1,059 $ 919 Research and development $ 2,609 2,054 4,705 4,653 Sales and marketing $ 2,812 2,424 5,260 5,198 General and administrative $ 2,655 1,090 4,905 3,127 Total stock-based compensation expense $ 8,586 $ 6,039 $ 15,929 $ 13,897

Net Income (Loss) (Tables)

Net Income (Loss) (Tables)	6 Months Ended
	Jun. 27, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table presents the computation of basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except per share data): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Numerator: Net income (loss) attributable to common stockholders $ 38 $ (32,486 ) $ (657 ) $ (40,704 ) Denominator: Weighted average shares used for basic net income (loss) per share computation 33,429 32,116 33,203 31,895 Weighted average effect of dilutive securities: Stock options 1,079 — — — RSUs 738 — — — ESPP purchase rights 420 — — — Weighted average shares used for diluted net income (loss) per share computation 35,666 32,116 33,203 31,895 Net income (loss) per share attributable to common stockholders : Basic $ — $ (1.01 ) $ (0.02 ) $ (1.28 ) Diluted $ — $ (1.01 ) $ (0.02 ) $ (1.28 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	The weighted average number of shares outstanding used in the computation of diluted net income (loss) per share does not include the effect of the following shares of potentially outstanding common stock because the effect would have been anti-dilutive for the periods presented (in thousands): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 Equity awards to purchase common stock 1,058 4,358 4,771 4,520

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 27, 2015
Segment Reporting [Abstract]
Revenue and Long-Lived Assets by Geographic Region	The following table summarizes the Company’s revenue by geographic region, based on the location to where the product was shipped (in thousands): Three Months Ended Six Months Ended June 27, 2015 June 28, 2014 June 27, 2015 June 28, 2014 United States $ 37,798 $ 25,152 $ 70,431 $ 49,573 Rest of Americas 2,957 2,321 6,048 4,018 Europe, Middle East and Africa 6,780 4,826 14,262 8,530 Asia Pacific 3,911 2,552 7,558 4,490 Total $ 51,446 $ 34,851 $ 98,299 $ 66,611 The Company’s long-lived assets by geographic region are summarized as follows (in thousands): As of June 27, 2015 December 27, 2014 United States $ 6,800 $ 7,218 Other 215 169 Total $ 7,015 $ 7,387

Summary of Significant Accoun25

Summary of Significant Accounting Policies - Customers Representing Major Revenue and Accounts Receivable (Detail) - customer	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
Total Revenue
Concentration Risk [Line Items]
Number of customers accounting for more than 10% of revenue			0	0
Total Revenue | Customer A (distributor)
Concentration Risk [Line Items]
Concentration risk	48.00%	43.00%	43.00%	45.00%
Total Revenue | Customer B (distributor)
Concentration Risk [Line Items]
Concentration risk	18.00%	16.00%	20.00%	15.00%
Accounts Receivable | Customer A (distributor)
Concentration Risk [Line Items]
Concentration risk			28.00%
Accounts Receivable | Customer B (distributor)
Concentration Risk [Line Items]
Concentration risk			23.00%		36.00%
Accounts Receivable | End User Customer [Member]
Concentration Risk [Line Items]
Concentration risk			15.00%

Summary of Significant Accoun26

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
Schedule Of Significant Accounting Policies [Line Items]
Inventory write-down	$ 500	$ 600	$ 1,012	$ 2,437
Deferred costs	$ 1,500		$ 1,500		$ 800
Product warranties period (in years)			5 years
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Services revenue, recognition period (in years)			1 year
Maximum
Schedule Of Significant Accounting Policies [Line Items]
Services revenue, recognition period (in years)			5 years

Fair Value Measurements - Compo

Fair Value Measurements - Components of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Cash and cash equivalents:
Cash and cash equivalents	$ 96,759	$ 38,941
Short-term investments:
Short-term investments	82,367	110,465
Money market funds
Cash and cash equivalents:
Cash and cash equivalents	40,896	15,976
Corporate debt securities
Short-term investments:
Short-term investments	30,808	58,707
Cash Equivalents
Cash and cash equivalents:
Cash and cash equivalents	40,896	15,976
Cash
Cash and cash equivalents:
Cash and cash equivalents	55,863	22,965
U.S. agency debt securities
Short-term investments:
Short-term investments	25,550	31,779
U.S. government securities
Short-term investments:
Short-term investments	26,009	19,979
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Cash and cash equivalents:
Cash and cash equivalents	40,896	15,976
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash Equivalents
Cash and cash equivalents:
Cash and cash equivalents	40,896	15,976
Significant Other Observable Inputs (Level 2)
Short-term investments:
Short-term investments	82,367	110,465
Significant Other Observable Inputs (Level 2) | Corporate debt securities
Short-term investments:
Short-term investments	30,808	58,707
Significant Other Observable Inputs (Level 2) | Cash Equivalents
Cash and cash equivalents:
Cash and cash equivalents	0	0
Significant Other Observable Inputs (Level 2) | U.S. agency debt securities
Short-term investments:
Short-term investments	25,550	31,779
Significant Other Observable Inputs (Level 2) | U.S. government securities
Short-term investments:
Short-term investments	$ 26,009	$ 19,979

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	Jun. 27, 2015USD ($)security	Dec. 27, 2014USD ($)security
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$ 0
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments Measured at Amortized Costs, Gross Unrealized Gain, Gross Unrealized Loss and Fair Value by Significant Investment Categories (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Cash and Cash Equivalents
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	$ 96,759	$ 38,941
Fair Value	96,759	38,941
Cash and Cash Equivalents | Money market funds
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	40,896	15,976
Fair Value	40,896	15,976
Cash and Cash Equivalents | Cash
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	55,863	22,965
Fair Value	55,863	22,965
Short-term Investments
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	82,357	110,559
Gross Unrealized Gains	33	12
Gross Unrealized Losses	(23)	(106)
Fair Value	82,367	110,465
Short-term Investments | Corporate debt securities
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	30,828	58,777
Gross Unrealized Gains	1	4
Gross Unrealized Losses	(21)	(74)
Fair Value	30,808	58,707
Short-term Investments | U.S. agency debt securities
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	25,542	31,800
Gross Unrealized Gains	9	1
Gross Unrealized Losses	(1)	(22)
Fair Value	25,550	31,779
Short-term Investments | U.S. government securities
Cash And Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost Basis	25,987	19,982
Gross Unrealized Gains	23	7
Gross Unrealized Losses	(1)	(10)
Fair Value	$ 26,009	$ 19,979

Fair Value Measurements - Contr

Fair Value Measurements - Contractual Maturity Date of Short-Term Investments (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Contractual Maturity Date of Short-Term Investments [Abstract]
Due within one year	$ 109,665	$ 90,555
Due between one and five years	13,598	35,886
Total	$ 123,263	$ 126,441

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 183	$ 433
Finished goods	4,676	6,118
Total inventories	$ 4,859	$ 6,551

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued employee related costs	$ 14,551	$ 16,021
Accrued inventory and other purchases	1,663	1,830
Accrued professional services	891	761
Other accruals	5,636	4,226
Total accrued liabilities	$ 22,741	$ 22,838

Balance Sheet Components - Ac33

Balance Sheet Components - Accrued Warranty (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014	Dec. 28, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Product Warranty Accrual	$ 999	$ 712	$ 875	$ 686
Movement in Standard Product Warranty Accrual [Roll Forward]
Product Warranty Accrual, Warranties Issued	593	482
Product Warranty Accrual, Payments	$ 469	$ 456

Balance Sheet Components - Defe

Balance Sheet Components - Deferred Revenue (Detail) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 68,722	$ 55,505
Deferred service revenue
Deferred Revenue Arrangement [Line Items]
Deferred revenue	58,350	51,699
Deferred product revenue
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 10,372	$ 3,806

Balance Sheet Components - Accu

Balance Sheet Components - Accumulated Other Comprehensive Income (Loss) (Detail)	6 Months Ended
	Jun. 27, 2015USD ($)
Net Unrealized Gains (Losses)
Beginning balance	$ (94,000)
Other comprehensive income (loss), before tax	104,000
Ending balance	10,000
Income Tax Provision
Tax impact on unrealized gains or losses	0
Tax impact on total other comprehensive income	0
Reclassifications out of accumulated other comprehensive income	0
Accumulated Net Unrealized Investment Gain (Loss)
Net Unrealized Gains (Losses)
Other comprehensive income (loss), before tax	$ 104,000

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments Under Non-Cancelable Operating Leases (Detail) $ in Thousands	Jun. 27, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2015 (remaining six months)	$ 1,813
2,016	3,370
2,017	3,333
2,018	957
2,019	82
Total	$ 9,555

Commitments and Contingencies37

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 0.8	$ 0.6	$ 1.5	$ 1.4
Purchase commitments with vendors	$ 3.2		$ 3.2		$ 3.5

Preferred Stock and Stockhold38

Preferred Stock and Stockholders' Equity - Preferred, Common and Treasury Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 27, 2015	Dec. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common Stock Votes Per Share	$ 1
Common stock, shares issued	33,489,470	32,641,500
Treasury Stock, Shares	8,109,848	8,109,848
Treasury Stock, Value	$ 12,469	$ 12,469
Treasury Stock Acquired, Average Cost Per Share	$ 1.53	$ 1.53
Preferred stock, shares outstanding	0	0
Common stock, shares outstanding	33,489,470	32,641,500

Preferred Stock and Stockhold39

Preferred Stock and Stockholders' Equity - Equity Award Plans Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 27, 2015USD ($)$ / sharesshares	Jun. 28, 2014USD ($)	Jun. 27, 2015USD ($)Period$ / sharesshares	Jun. 28, 2014USD ($)$ / shares	Dec. 27, 2014$ / sharesshares	May. 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense | $	$ 8,586	$ 6,039	$ 15,929	$ 13,897
Share Based Compensation Arrangement By Share Based Payment Award Option Vested In Period Fair Value | $ / shares			$ 10.18	$ 9.18
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,375,313		2,375,313		2,386,412
ESPP purchase right:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Ownership Plan (ESOP), Plan Description			The ESPP provides for a 24-month offering period comprised of four purchase periods of approximately six months. Employees are able to purchase shares at 85% of the lower of the market value of the Company's common stock (i) at the date of commencement of the offering period or (ii) at the last day of the purchase period.
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 1,700		$ 1,700
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	439,422		439,422			439,422
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized					439,422
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum			1.50%
Employee Stock Purchase Plan Maximum Percentage Of Compensation To Purchase Shares By Eligible Participants			15.00%
Employee Stock Purchase Plan Percentage Of Purchase Price From Market Value			85.00%
Employee Stock Purchase Plan Offered Period			24 months
Share-Based Compensation Arrangement by Share-based Payment Award, Number of Purchase Periods in subscription | Period			4
Share-Based Compensation Arrangement by Share-based Payment Award, Number of Purchase Periods | Period			1
Share-based Compensation Arrangement by Share-based Payment Award, Term of Purchase Period			6 months
Total stock-based compensation expense | $	$ 700	$ 1,100	$ 1,400	$ 2,800
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			273,301
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased | $ / shares	$ 9.54		$ 9.54
Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Description			Vested options may be exercised up to ten years from the vesting commencement date.
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 5,600		$ 5,600
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 21,800		$ 21,800
Share Price | $ / shares	$ 33.82		$ 33.82		$ 17.47
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			1 year
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	31,766		31,766		36,495
Equity Incentive Plan Twenty Thirteen [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Description			(i) 1,464,740 shares, (ii) 5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year, or (iii) such other amount as determined by the Board. Vested but unexercised options, under the 2013 Equity Plan, expire three months after termination of service with the Company.
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,464,740		1,464,740		1,464,740	2,929,481
Share-based Compensation Arrangement by Share-based Payment Award, Other Share Increase (Decrease)			4,967,172
Share Based Compensation Arrangement By Share Based Payment Award Number Of Additional Shares Allowable For Future Authorization Each Year			1,464,740
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum			5.00%
Share Based Compensation Arrangement By Share Based Payment Award Options Maximum Exercisable Term For General Termination			3 months
Equity Incentive Plan Twenty Thirteen [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	3,206,027		3,206,027
Equity Incentive Plan Twenty Thirteen [Member] | Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period			10 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period After Termination of Employment			3 months
Equity Incentive Plan Twenty Fifteen [Member] | Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period			7 years
Equity Incentive Plan Twenty Twelve [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	1,351,190		1,351,190
Equity Incentive Plan Twenty Twelve [Member] | Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period After Termination of Employment			30 days
Unit Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Description			Vested options may be exercised up to ten years from the vesting commencement date, as defined in the Option Plan. Vested but unexercised options, under the Option Plan, expire 30 days after termination of employment with the Company.

Preferred Stock and Stockhold40

Preferred Stock and Stockholders' Equity - Stock Option Activity Table (Details) - Equity Award [Domain] - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 27, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,386,412
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	408,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(340,889)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	(78,210)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,375,313	2,386,412
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	2,212,151
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	985,259
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 12.91
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	21.44
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	8.08
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	10.08
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	15.16	$ 12.91
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	14.90
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 12.40
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	7 years 6 months	8 years 2 months 15 days
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	7 years 6 months	8 years 2 months 15 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	7 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	7 years 3 months 10 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 14,403
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	44,291	$ 14,403
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	41,846
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 21,104

Preferred Stock and Stockhold41

Preferred Stock and Stockholders' Equity - RSU Activity Table (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 27, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance - December 27, 2014	1,733,225
RSUs granted	1,019,205
RSUs vested	(381,419)
RSUs canceled	(187,552)
Balance - June 27, 2015	2,183,459	1,733,225
Vested and expected to vest — June 27, 2015	1,896,384
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 18.78
RSUs granted	22.73
RSUs vested	19.09
RSUs canceled	22.31
Balance - December 27, 2014	20.27	$ 18.78
Vested and expected to vest — June 27, 2015	$ 20.09
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms	1 year 4 months 24 days	1 year 3 months 7 days
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms	1 year 4 months 24 days	1 year 3 months 7 days
Vested and expected to vest — June 27, 2015	1 year 3 months 10 days
Balance - December 27, 2014	$ 30,279
Balance - June 27, 2015	73,845	$ 30,279
Vested and expected to vest — June 27, 2015	$ 64,136

Preferred Stock and Stockhold42

Preferred Stock and Stockholders' Equity - Fair Value of Option Awards amd ESPP Purchase Rights Granted (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per award (in US$ per share)	$ 0		$ 0	$ 0
Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		5 years 3 months 21 days
Risk-free interest rate	0.00%	1.70%
Expected volatility (percent)	0.00%	59.40%	56.00%	59.40%
Expected dividend rate (percent)	0.00%			0.00%
Grant date fair value per award (in US$ per share)	$ 0	$ 9.20
ESPP purchase right:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend rate (percent)	0.00%	0.00%	0.00%	0.00%
Maximum | Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years 1 month 7 days		6 years 1 month 7 days
Risk-free interest rate		1.80%		1.90%
Expected volatility (percent)				61.90%
Grant date fair value per award (in US$ per share)		$ 9.86		$ 17.67
Maximum | ESPP purchase right:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	2 years	2 years	2 years	2 years
Risk-free interest rate	0.70%	0.30%	0.70%	0.30%
Expected volatility (percent)	50.30%	52.70%	50.30%	52.70%
Grant date fair value per share (in US$ per share)	$ 9.18	$ 13.60	$ 9.18	$ 13.06
Minimum | Stock option awards:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			4 years 7 months 7 days	5 years 3 months 18 days
Risk-free interest rate			1.60%	1.70%
Grant date fair value per award (in US$ per share)			$ 10.11	$ 9.20
Minimum | ESPP purchase right:
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months	6 months	6 months
Risk-free interest rate	0.07%	0.10%	0.10%	0.10%
Expected volatility (percent)	37.60%	44.80%	37.60%	44.80%
Grant date fair value per share (in US$ per share)	$ 5.48	$ 8.23	$ 5.48	$ 8.23

Preferred Stock and Stockhold43

Preferred Stock and Stockholders' Equity - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 8,586	$ 6,039	$ 15,929	$ 13,897
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	510	471	1,059	919
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,609	2,054	4,705	4,653
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,812	2,424	5,260	5,198
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,655	$ 1,090	$ 4,905	$ 3,127

Defined Contribution Plans - Ad

Defined Contribution Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Postemployment Benefits [Abstract]
Defined Benefit Plan, Contributions by Employer	$ 0.4	$ 0.6	$ 0.8	$ 1.2

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Income Tax Disclosure [Abstract]
Income tax provision	$ (99)	$ (24,727)	$ (187)	$ (21,027)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount				$ 24,600

Net Income (Loss) (Details)

Net Income (Loss) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ 38	$ (32,486)	$ (657)	$ (40,704)
Weighted Average Number of Shares Outstanding, Basic	33,429	32,116	33,203	31,895
Diluted (in shares)	35,666	32,116	33,203	31,895
Earnings Per Share, Basic	$ 0	$ (1.01)	$ (0.02)	$ (1.28)
Earnings Per Share, Diluted	$ 0	$ (1.01)	$ (0.02)	$ (1.28)
Stock option awards:
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,079	0	0	0
Option Plans Awards To Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,058	4,358	4,771	4,520
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	738	0	0	0
ESPP purchase right:
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	420	0	0	0

Segment Information - Additiona

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 27, 2015Segment
Segment Reporting [Abstract]
Number of segments	1

Segment Information - Revenue a

Segment Information - Revenue and Long-Lived Assets by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	$ 51,446	$ 34,851	$ 98,299	$ 66,611
Long-lived assets	7,015		7,015		$ 7,387
United States
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	37,798	25,152	70,431	49,573
Long-lived assets	6,800		6,800		7,218
Rest of Americas
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	2,957	2,321	6,048	4,018
Europe, Middle East and Africa
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	6,780	4,826	14,262	8,530
Asia Pacific
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	3,911	$ 2,552	7,558	$ 4,490
Other
Segment Reporting Revenue Reconciling Item [Line Items]
Long-lived assets	$ 215		$ 215		$ 169