Harmonic (HLIT) 10-Q 6 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 29, 2018	Jul. 27, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 29, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	HLIT
Entity Registrant Name	HARMONIC INC
Entity Central Index Key	851,310
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		86,031,433

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 54,098	$ 57,024
Accounts receivable, net	82,635	69,844
Inventories	22,994	25,976
Prepaid expenses and other current assets	19,377	18,931
Total current assets	179,104	171,775
Property and equipment, net	25,631	29,265
Goodwill	241,176	242,827
Intangibles, net	17,010	21,279
Other long-term assets	42,863	42,913
Total assets	505,784	508,059
Current liabilities:
Other debts and capital lease obligations, current	1,723	7,610
Accounts payable	28,992	33,112
Income taxes payable	560	233
Deferred revenue	56,278	52,429
Accrued and other current liabilities	51,221	48,705
Total current liabilities	138,774	142,089
Convertible notes, long-term	111,702	108,748
Other debts and capital lease obligations, long-term	14,318	15,336
Income taxes payable, long-term	1,086	917
Other non-current liabilities	19,169	22,626
Total liabilities	285,049	289,716
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.001 par value, 150,000 shares authorized; 85,439 and 82,554 shares issued and outstanding at June 29, 2018 and December 31, 2017, respectively	85	83
Additional paid-in capital	2,283,649	2,272,690
Accumulated deficit	(2,062,988)	(2,057,812)
Accumulated other comprehensive income (loss)	(11)	3,382
Total stockholders’ equity	220,735	218,343
Total liabilities and stockholders’ equity	$ 505,784	$ 508,059

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 29, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	85,439,000	82,554,000
Common stock, shares outstanding	85,439,000	82,554,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Total net revenue	$ 99,160	$ 82,315	$ 189,287	$ 165,258
Total cost of revenue	47,557	48,500	90,501	91,035
Total gross profit	51,603	33,815	98,786	74,223
Operating expenses:
Research and development	21,542	27,055	44,999	51,937
Selling, general and administrative	27,988	32,625	59,151	67,256
Amortization of intangibles	800	780	1,604	1,554
Restructuring and related charges	631	777	1,717	2,056
Total operating expenses	50,961	61,237	107,471	122,803
Income (loss) from operations	642	(27,422)	(8,685)	(48,580)
Interest expense, net	(2,863)	(2,680)	(5,620)	(5,270)
Other income (expense), net	199	(819)	(333)	(1,330)
Loss before income taxes	(2,022)	(30,921)	(14,638)	(55,180)
Provision for income taxes	891	579	1,969	347
Net loss	$ (2,913)	$ (31,500)	$ (16,607)	$ (55,527)
Net loss per share:
Basic and diluted	$ (0.03)	$ (0.39)	$ (0.20)	$ (0.69)
Shares used in per share calculation:
Basic and diluted	85,304	80,590	84,616	80,203
Product
Total net revenue	$ 60,599	$ 50,190	$ 115,973	$ 100,594
Total cost of revenue	31,251	32,005	57,860	58,107
Service [Member]
Total net revenue	38,561	32,125	73,314	64,664
Total cost of revenue	$ 16,306	$ 16,495	$ 32,641	$ 32,928

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Net loss	$ (2,913)	$ (31,500)	$ (16,607)	$ (55,527)
Other comprehensive income (loss) before tax:
Unrealized loss arising during the period	0	(114)	0	(613)
Change in foreign currency translation adjustments	(4,758)	3,994	(3,024)	4,883
Other comprehensive income before tax	(4,758)	3,880	(3,024)	4,270
Less: Provision for income taxes	369	0	369	2
Other comprehensive income, net of tax	(5,127)	3,880	(3,393)	4,268
Total comprehensive loss	$ (8,040)	$ (27,620)	$ (20,000)	$ (51,259)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (16,607)	$ (55,527)
Adjustments to reconcile net loss to net cash provided by operating activities:
Amortization of intangibles	4,194	4,144
Depreciation	6,771	7,139
Stock-based compensation	8,769	7,387
Amortization of discount on convertible debt and issuance cost	2,954	2,676
Restructuring, asset impairment and loss on retirement of fixed assets	93	228
Amortization of non-cash warrant	395	416
Deferred income taxes, net	530	(38)
Foreign currency adjustments	(1,042)	1,131
Provision for excess and obsolete inventories	822	5,094
Allowance for doubtful accounts and returns	623	3,274
Other non-cash adjustments, net	64	189
Changes in operating assets and liabilities:
Accounts receivable	(13,572)	23,479
Inventories	2,000	2,912
Prepaid expenses and other assets	1,897	5,933
Accounts payable	(4,187)	1,434
Deferred revenue	9,378	1,308
Income taxes payable	503	228
Accrued and other liabilities	(337)	(8,793)
Net cash provided by operating activities	3,248	2,614
Cash flows from investing activities:
Proceeds from maturities of investments	0	3,106
Proceeds from sales of investments	0	3,792
Purchases of property and equipment	(3,181)	(5,943)
Net cash (used in) provided by investing activities	(3,181)	955
Cash flows from financing activities:
Proceeds from other debts and capital leases	0	164
Repayment of other debts and capital leases	(6,176)	(6,650)
Proceeds from common stock issued to employees	2,366	2,117
Payment of tax withholding obligations related to net share settlements of restricted stock units	(54)	(2,726)
Net cash used in financing activities	(3,864)	(7,095)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(588)	935
Net decrease in cash, cash equivalents and restricted cash	(4,385)	(2,591)
Cash, cash equivalents and restricted cash at beginning of period	58,757	57,420
Cash, cash equivalents and restricted cash at end of period	54,372	54,829
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Total Cash, Cash Equivalents and Restricted Cash	$ 58,757	$ 57,420

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 29, 2018
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited condensed consolidated financial statements, in the opinion of management, include all adjustments (consisting only of normal recurring adjustments) which Harmonic Inc. (“Harmonic,” or the “Company”) considers necessary to present fairly the results of operations for the interim periods covered and the consolidated financial condition of the Company at the date of the balance sheets. This Quarterly Report on Form 10-Q should be read in conjunction with the Company’s audited consolidated financial statements contained in the Company’s Annual Report on Form 10-K, which was filed with the Securities and Exchange Commission on March 5, 2018 (the “2017 Form 10-K”). The interim results presented herein are not necessarily indicative of the results of operations that may be expected for the full fiscal year ending December 31, 2018, or any other future period. The Company’s fiscal quarters are based on 13-week periods, except for the fourth quarter, which ends on December 31. The condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The condensed consolidated balance sheet as of December 31, 2017 was derived from audited financial statements, and the unaudited condensed consolidated financial statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those requirements, certain footnotes or other financial information that are normally required by generally accepted accounting principles in the United States of America (“U.S. GAAP”) have been condensed or omitted. Reclassifications Certain prior period balances have been reclassified to conform to the current period’s presentation. These reclassifications did not have a material impact on previously reported financial statements. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make 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 revenue and expenses during the reporting period. The Company’s reported financial positions or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information. Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 to its audited Consolidated Financial Statements included in the 2017 Form 10-K. There have been no significant changes to these policies during the six months ended June 29, 2018 other than those disclosed in Note 2, “Recently Adopted Accounting Pronouncements”.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 29, 2018
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Recently Adopted Accounting Pronouncements ASC Topic 606, “Revenue from Contracts with Customers” On January 1, 2018, the Company adopted ASC 606, Revenue from Contracts with Customers (“Topic 606”), using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for the reporting period beginning January 1, 2018 are presented under Topic 606, while prior period amounts are not restated and continue to be reported in accordance with our historic accounting under ASC 605, Revenue Recognition (“Topic 605”). Under Topic 606, the Company began to recognize a contract asset for satisfied performance obligations that do not provide the Company with an unconditional right to consideration, which was restricted under the previous standard. In addition, the Company changed its revenue recognition for professional services from a completed contract method to a percentage of completion method. The cumulative effect of initially applying Topic 606 to the Company’s condensed consolidated balance sheet on January 1, 2018 was as follows (in thousands): CONDENSED CONSOLIDATED BALANCE SHEETS Balance as of December 31, 2017 Cumulative Impact from Adopting Topic 606 Balance as of January 1, 2018 ASSETS Accounts receivable, net $ 69,844 $ 1,781 $ 71,625 Prepaid expenses and other current assets 18,931 3,578 22,509 Other long-term assets 42,913 773 43,686 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue $ 52,429 $ (4,826 ) $ 47,603 Other non-current liabilities 22,626 (473 ) 22,153 Accumulated deficit (2,057,812 ) 11,431 (2,046,381 ) The impact from adopting Topic 606 on the Company’s condensed consolidated financial statements was as follows (in thousands): Three months ended June 29, 2018 Six months ended June 29, 2018 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 As Reported Previous Accounting Guidance Impact from Adopting Topic 606 Total net revenue $ 99,160 $ 98,714 $ 446 $ 189,287 $ 188,037 $ 1,250 Total cost of revenue 47,557 47,316 241 90,501 90,141 360 Total gross profit 51,603 51,398 205 98,786 97,896 890 Operating expenses: Selling, general and administrative 27,988 28,570 (582 ) 59,151 59,541 (390 ) Income (loss) from operations 642 (145 ) 787 (8,685 ) (9,965 ) 1,280 Loss before income taxes (2,022 ) (2,809 ) 787 (14,638 ) (15,918 ) 1,280 Net loss (2,913 ) (3,700 ) 787 (16,607 ) (17,887 ) 1,280 As of June 29, 2018 CONDENSED CONSOLIDATED BALANCE SHEETS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 ASSETS Accounts receivable, net 82,635 78,065 $ 4,570 Prepaid expenses and other current assets 19,377 15,918 3,459 Other long-term assets 42,863 42,360 503 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue 56,278 60,032 (3,754 ) Other non-current liabilities 19,169 19,594 (425 ) Accumulated deficit (2,062,988 ) (2,075,699 ) 12,711 Revenue Recognition The Company’s principal sources of revenue are from the sale of hardware, software, hardware and software maintenance contracts, and end-to-end solutions, encompassing design, manufacture, test, integration and installation of products. The Company also derives recurring revenue from subscriptions, which are comprised of subscription fees from customers utilizing the Company’s cloud-based media processing solutions. Revenue from contracts with customers is recognized using the following five steps: a) Identify the contract(s) with a customer; b) Identify the performance obligations in the contract; c) Determine the transaction price; d) Allocate the transaction price to the performance obligations in the contract; and e) Recognize revenue when (or as) the Company satisfies a performance obligation. A contract contains a promise (or promises) to transfer goods or services to a customer. A performance obligation is a promise (or a group of promises) that is distinct. The transaction price is the amount of consideration a Company expects to be entitled from a customer in exchange for providing the goods or services. The unit of account for revenue recognition is a performance obligation (a good or service). A contract may contain one or more performance obligations. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. Otherwise performance obligations will be combined with other promised goods or services until the Company identifies a bundle of goods or services that is distinct. The transaction price is allocated to all the separate performance obligations in an arrangement. It reflects the amount of consideration to which the Company expects to be entitled in exchange for transferring goods or services, which may include an estimate of variable consideration to the extent that it is probable of not being subject to significant reversals in the future based on the Company’s experience with similar arrangements. The transaction price also reflects the impact of the time value of money if there is a significant financing component present in an arrangement. The transaction price excludes amounts collected on behalf of third parties, such as sales taxes. Revenue is recognized when the Company satisfies each performance obligation by transferring control of the promised goods or services to the customer. Goods or services can transfer at a point in time or over time depending on the nature of the arrangement. Deferred revenue represents the Company’s obligation to transfer goods or services to a customer for which the Company has received consideration (or an amount of consideration is due) from the customer. Our payment terms vary by the type and location of our customer and the products or services offered. The term between invoicing and when payment is due is not significant. For certain products or services and customer types, we require payment before the products or services are delivered to the customer. During the three and six months ended June 29, 2018, the Company recognized $24.1 million and $44.0 million of revenue, respectively, that were included in Deferred revenue at the beginning of each respective period. Contract assets exist when the Company has satisfied a performance obligation but does not have an unconditional right to consideration (e.g., because the entity first must satisfy another performance obligation in the contract before it is entitled to invoice the customer). Contract assets are reported as a component of “Prepaid expenses and other current assets” on the Condensed Consolidated Balance Sheets. See Note 6, “Balance Sheet Components’ for additional information. Shipping and handling costs are accounted for as a fulfillment cost and are recorded in cost of revenue in the Company’s Condensed Consolidated Statements of Operations. Hardware and Software. Revenue from the sale of hardware and software products is recognized when the control is transferred. For most of the Company’s product sales (including sales to distributors and system integrators), the control is transferred at the time the product is shipped or delivery has occurred because the customer has significant risks and rewards of ownership of the asset and the Company has a present right to payment at that time. The Company’s agreements with the distributors and system integrators have terms which are generally consistent with the standard terms and conditions for the sale of the Company’s equipment to end users, and do not provide for product rotation or pricing allowances, as are typically found in agreements with stocking distributors. We offer trade-in rights which are specifically identified and accrued for at the end of the period through contra-revenue. Arrangements with Multiple Performance Obligations. The Company has revenue arrangements that include multiple performance obligations. The Company allocates transaction price to all separate performance obligations based on their relative standalone selling prices (“SSP”). The Company’s best evidence for SSP is the price the Company charges for that good or service when the Company sells it separately in similar circumstances to similar customers. If goods or services are not always sold separately, the Company uses the best estimate of SSP in the allocation of transaction price. The objective of determining the best estimate of SSP is to estimate the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The Company’s process for determining best estimate of SSP involves management’s judgment, and considers multiple factors including, but not limited to, major product groupings, geographies, gross margin objectives and pricing practices. Pricing practices taken into consideration include contractually stated prices, discounts offered and applicable price lists. These factors may vary over time, depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change or should future facts and circumstances lead the Company to consider additional factors, the Company’s best estimate of SSP may also change. Solution Sales. Solution sales for the design, manufacture, test, integration and installation of products, including equipment acquired from third parties to be integrated with Harmonic’s products, that are customized to meet the customer’s specifications are accounted for based on the percentage-of-completion basis, using the input method. Some of our arrangements may include acceptance provisions that require testing of the solution against specific performance criteria. The Company performs a detailed evaluation to determine whether the arrangement involves performance criteria based on our standard performance criteria. The Company has a long-standing history of entering into contractual arrangements to deliver the solution sales based on standard performance criteria. For this type of arrangement, we consider the customer acceptance clause not substantive and recognize product revenue when the customer takes possession on the product and recognize service on a percentage-of-completion basis. However, if the solution results in significant production, modification or customization, we consider the arrangement as a single performance obligation and recognize the revenue at a point in time, depending on the complexity of the solution and nature of acceptance. Professional services. Revenue from professional services is recognized over time, on the percentage-of-completion basis using the input method. Input method. The use of the input method requires the Company to make reasonably dependable estimates. We use the input method based on labor hours, where revenue is calculated based on the percentage of total hours incurred in relation to total estimated hours at completion of the contract. The input method is reasonable because the hours best reflect the Company’s efforts toward satisfying the performance obligation over time. As circumstances change over time, the Company updates its measure of progress to reflect any changes in the outcome of the performance obligation. Such changes to an entity’s measure of progress are accounted for as a change in accounting estimates. Support and maintenance. Support and maintenance services are satisfied ratably over time as the customer simultaneously receives and consumes the benefits of the services. As a result, support and maintenance revenue is recognized on a straight line basis over the period of the contract. Contract costs . The incremental costs of obtaining a contract are capitalized if the costs are expected to be recovered. Costs that are recognized as assets are amortized straight-line over the period as the related goods or services transfer to the customer. Costs incurred to fulfill a contract are capitalized if they are not covered by other relevant guidance, relate directly to a contract, will be used to satisfy future performance obligations, and are expected to be recovered. The Company recorded a net decrease to the opening balance of accumulated deficit of $1.4 million as of January 1, 2018 for capitalizing contract costs due to the cumulative impact of adopting Topic 606 for sales commissions related to customer contracts with an amortization period in excess of one year. Anticipated contract renewals, amendments, and follow-on contracts with the same customer are considered when determining the period of amortization. The net capitalized contract costs as of June 29, 2018 were $1.8 million , of which $1.3 million and $ 0.5 million were reported as components of “Prepaid expenses and other current assets” and “Other long-term assets” on the Condensed Consolidated Balance Sheets, respectively. The amortization of the capitalized contract costs during the three and six months ended June 29, 2018 was $0.3 million and $0.5 million , respectively. Significant Judgments . The Company has revenue arrangements that include promises to transfer multiple products and services to a customer. The Company may exercise significant judgment when determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together. The Company allocates the transaction price to all separate performance obligations based on the SSP of each obligation. The Company’s best evidence for SSP is the price the Company charges for that good or service when the Company sells it separately in similar circumstances to similar customers. If goods or services are not always sold separately, the Company uses the best estimate of SSP in the allocation of the transaction price. The objective of determining the best estimate of SSP is to estimate the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The Company’s process for determining the best estimate of SSP involves management’s judgment, and considers multiple factors including, but not limited to, major product groupings, geographies, gross margin objectives and pricing practices. Pricing practices taken into consideration include contractually stated prices, discounts and applicable price lists. These factors may vary over time, depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change or should future facts and circumstances lead the Company to consider additional factors, the Company’s best estimate of SSP may also change. Practical Expedients and Exemptions. Under Topic 606, incremental costs of obtaining a contract such as sales commissions are capitalized if they are expected to be recovered, and amortized on a straight-line basis. Expensing these costs as incurred is not permitted unless they qualify for a practical expedient. Other than capitalized costs of obtaining subscription contracts which are amortized regardless of the life of expected amortization period, the Company elected the practical expedient to expense the costs to obtain all other contracts as incurred, when the life of the expected amortization period is one year or less by using a portfolio approach. The Company elected the practical expedient under Topic 606 to not disclose the transaction price allocated to remaining performance obligations, since the majority of the Company’s arrangements have original expected durations of one year or less, or the invoicing corresponds to the value of the Company’s performance completed to date. The Company elected the practical expedient that allows the Company to not assess a contract for a significant financing component if the period between the customer’s payment and the transfer of the goods or services is one year or less. See Note 14, “Segment Information” for further disaggregated revenue information. Other Recently Adopted Accounting Pronouncements In January 2016, the Financial Accounting Standards Board (“FASB) issued Accounting Standards Updated (“ASU”) No. 2016-01, Financial Instruments (Topic 825): Recognition and Measurement of Financial Assets and Financial Liabilities, which requires equity investments to be measured at fair value with changes in fair value recognized in net income and simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. The Company adopted this new standard in the first quarter of fiscal 2018, and the adoption did not have a material impact on its condensed consolidated financial statements. See Note 3, “Investments in Equity Securities” for additional information. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, which requires entities to present the aggregate changes in cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, the statement of cash flows will be required to present restricted cash and restricted cash equivalents as a part of the beginning and ending balances of cash and cash equivalents. The Company adopted this new standard in the first quarter of fiscal 2018 on a retrospective basis. The Company’s total restricted cash balance was $0.3 million and $1.7 million as of June 29, 2018 and December 31, 2017, respectively. The Company’s total restricted cash balance was $1.9 million and $1.8 million as of June 30, 2017 and December 31, 2016, respectively. These restricted cash balances are presented as a part of the ending and beginning balances of cash, cash equivalents and restricted cash on the Company’s Condensed Consolidated Statements of Cash Flows for the corresponding periods. See Note 6, “Balance Sheet Components” for additional information. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The objective of ASU 2017-01 is to clarify the definition of a business in order to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The Company adopted this new standard in the first quarter of fiscal 2018, and the adoption had no impact on its condensed consolidated financial statements. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), to amend the existing accounting standard for lease accounting. Under this guidance, lessees and lessors should apply a “right-of-use” model in accounting for all leases (including subleases) and eliminate the concept of operating leases and off-balance sheet leases. The new leases standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2019 and early adoption is permitted. The Company will be required to recognize the right-of-use assets and liabilities of operating leases upon adoption of the new guidance. The Company continues to evaluate the effect of adopting this guidance on its consolidated financial statements and related disclosures. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which amends ASC Topic 842 to provide another transition method, allowing a cumulative effect adjustment to the opening balance of retained earnings during the period of adoption. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets and certain other instruments. For trade receivables and other instruments, the Company will be required to use a new forward-looking “expected loss” model. Additionally, credit losses on available-for-sale debt securities should be recorded through an allowance for credit losses limited to the amount by which fair value is below amortized cost. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2020 and early adoption is permitted. The adoption of the new ASU is not expected to have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The new ASU removes Step 2 of the goodwill impairment test and requires the assessment of fair value of individual assets and liabilities of a reporting unit to measure goodwill impairments. Goodwill impairment will then be the amount by which a reporting unit's carrying value exceeds its fair value. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2020 on a prospective basis, and early adoption is permitted. The Company is currently evaluating the impact of adopting the new ASU on its consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The new ASU expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should apply the requirements of Topic 718 to nonemployee awards except for specific guidance on inputs to an option pricing model and the attribution of cost. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2019 and early adoption is permitted. The adoption of the new ASU is not expected to have a material impact on the Company’s consolidated financial statements.

Investments in Equity Securitie

Investments in Equity Securities	6 Months Ended
	Jun. 29, 2018
Investments, All Other Investments [Abstract]
Investments in Equity Securities	INVESTMENTS IN EQUITY SECURITIES Vislink In 2014, the Company acquired a 3.3% interest in Vislink plc (“Vislink”), a U.K. public company listed on the AIM exchange, for $3.3 million . On February 3, 2017, Vislink completed the disposal of its hardware division and changed its name to Pebble Beach Systems (“PBS”). The Company does not have significant influence over PBS’s operational and financial policies. The carrying value of the investment in PBS was fully written off as of December 31, 2017. Beginning the first quarter of fiscal 2018, the Company adopted ASU No. 2016-01, Financial Instruments (Topic 825): Recognition and Measurement of Financial Assets and Financial Liabilities, which requires equity investments to be measured at fair value with changes in fair value recognized in net income. As a result of adopting this new standard, the Company started measuring the investment in PBS at fair value based on its quoted stock price on the AIM exchange. The Company recorded a gain on change in fair value of the investment in PBS to Other income (expense), net of $0.2 million and $0.2 million during both the three and six months ended June 29, 2018. Unconsolidated Variable Interest Entities (“VIE”) EDC In 2014, the Company acquired an 18.4% interest in Encoding.com, Inc. (“EDC”), a privately held video transcoding service company headquartered in San Francisco, California, for $3.5 million by purchasing EDC’s Series B preferred stock. EDC is considered a VIE but the Company determined that it is not the primary beneficiary of EDC. As a result, EDC is measured at its cost minus impairment, if any. The Company determined that there were no indicators at June 29, 2018 that the EDC investment was impaired.

Derivative and Hedgiing Activit

Derivative and Hedgiing Activities Derivative and Hedging Activities	6 Months Ended
	Jun. 29, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure	DERIVATIVES AND HEDGING ACTIVITIES The Company uses forward contracts to manage exposures to foreign currency exchange rates. The Company’s primary objective in holding derivative instruments is to reduce the volatility of earnings and cash flows associated with fluctuations in foreign currency exchange rates and the Company does not use derivative instruments for trading purposes. The use of derivative instruments exposes the Company to credit risk to the extent that the counterparties may be unable to meet their contractual obligations. As such, the potential risk of loss with any one counterparty is closely monitored by the Company. Derivatives Not Designated as Hedging Instruments (Balance Sheet Hedges) The Company’s balance sheet hedges consist of foreign currency forward contracts that generally mature within three months, are carried at fair value, and are used to minimize the short-term impact of foreign currency exchange rate fluctuation on cash and certain trade and inter-company receivables and payables. Changes in the fair value of these foreign currency forward contracts are recognized in “Other income (expense), net” in the Condensed Consolidated Statement of Operations and are largely offset by the changes in the fair value of the assets or liabilities being hedged. Losses on the non-designated derivative instruments recognized during the periods presented were as follows (in thousands): Three months ended Six months ended Financial Statement Location June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Derivatives not designated as hedging instruments: Losses recognized in income Other income (expense), net $ (1,268 ) $ (53 ) $ (1,382 ) $ (185 ) The U.S. dollar equivalents of all outstanding notional amounts of foreign currency forward contracts, including the Euro, British pound, Israeli shekel and Japanese yen, are summarized as follows (in thousands): June 29, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Purchase $ 24,743 $ 12,875 Sell $ 1,658 $ 1,509 The locations and fair value amounts of the Company’s derivative instruments reported in its Condensed Consolidated Balance Sheets are as follows (in thousands): Asset Derivatives Derivative Liabilities Balance Sheet Location June 29, 2018 December 31, 2017 Balance Sheet Location June 29, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Foreign currency contracts Prepaid expenses and other current assets $ 14 $ 33 Accrued and other current liabilities $ 298 $ 4 Total derivatives $ 14 $ 33 $ 298 $ 4 Offsetting of Derivative Assets and Liabilities The Company recognizes all derivative instruments on a gross basis in the Condensed Consolidated Balance Sheets. However, the arrangements with its counterparties allows for net settlement, which are designed to reduce credit risk by permitting net settlement with the same counterparty. As of June 29, 2018 , information related to the offsetting arrangements was as follows (in thousands): Gross Amounts of Derivatives Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Derivatives Gross Amounts of Derivatives Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivatives Presented in the Condensed Consolidated Balance Sheets Financial Instrument Net Amount Derivative assets $ 14 — $ 14 $ (14 ) $ — Derivative liabilities $ 298 — $ 298 $ (14 ) $ 284 In connection with foreign currency derivatives entered in Israel, the Company’s subsidiaries in Israel are required to maintain a compensating balance with their bank at the end of each month. The compensating balance arrangements do not legally restrict the use of cash and as of June 29, 2018 , the total compensating balance maintained was $1.0 million .

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 29, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The authoritative accounting guidance establishes a framework for measuring fair value and requires disclosure about the fair value measurements of assets and liabilities. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, in the principal or most advantageous market for the asset or liability, in an orderly transaction between market participants on the measurement date. This guidance requires the Company to classify and disclose assets and liabilities measured at fair value on a recurring basis, as well as fair value measurements of assets and liabilities measured on a nonrecurring basis in periods subsequent to initial measurement, in a three-tier fair value hierarchy as described below. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The guidance describes three levels of inputs that may be used to measure fair value: • Level 1 — Observable inputs that reflect quoted prices for identical assets or liabilities in active markets. • Level 2 — Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, 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. The forward exchange contracts are classified as Level 2 because they are valued using quoted market prices and other observable data for similar instruments in an active market. • 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 following table sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): Level 1 Level 2 Level 3 Total As of June 29, 2018 Cash equivalents Money market funds $ — $ — $ — $ — Derivative assets — 14 — 14 Other long-term assets Long-term investment 178 — — 178 Total assets measured and recorded at fair value $ 178 $ 14 $ — $ 192 Accrued and other current liabilities Derivative liabilities $ — $ 298 $ — $ 298 Total liabilities measured and recorded at fair value $ — $ 298 $ — $ 298 Level 1 Level 2 Level 3 Total As of December 31, 2017 Cash equivalents Money market funds $ 22 $ — $ — $ 22 Prepaid expenses and other current assets Derivative assets — 33 — 33 Total assets measured and recorded at fair value $ 22 $ 33 $ — $ 55 Accrued and other current liabilities Derivative liabilities $ — $ 4 $ — $ 4 Total liabilities measured and recorded at fair value $ — $ 4 $ — $ 4 The Company’s liability for the TVN VDP (as defined below) was $3.4 million and $5.1 million as of June 29, 2018 and December 31, 2017, respectively. This amount is not included in the table above because its fair value at inception, based on Level 3 inputs, was determined during the fourth quarter of fiscal 2016. There has been no recurring fair value re-measurement for this liability subsequently based on the applicable accounting guidance. See Note 8, “Restructuring and related charges-TVN VDP,” for additional information on the Company’s TVN VDP liabilities. The carrying value of the Company’s financial instruments, including cash equivalents, restricted cash, accounts receivable, accounts payable and accrued and other current liabilities, approximate fair value due to their short maturities. The Company uses the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. The fair value of the Company’s convertible notes is influenced by interest rates, the Company’s stock price and stock market volatility. The fair value of the Company’s convertible notes was approximately $133.6 million and $129.9 million as of June 29, 2018 and December 31, 2017, respectively, and represents a Level 2 valuation. The Company’s other debts assumed from the TVN acquisition are classified within Level 2 because these borrowings are not actively traded and the majority of them have a variable interest rate structure based upon market rates currently available to the Company for debt with similar terms and maturities, therefore, the carrying value of these debts approximate its fair value. The other debts, excluding capital leases, outstanding as of June 29, 2018 and December 31, 2017 were in the aggregate of $15.5 million and $21.8 million , respectively. (See Note 9, “Convertible Notes, Other debts and Capital Leases” for additional information). During the six months ended June 29, 2018 , there were no nonrecurring fair value measurements of assets and liabilities subsequent to initial recognition.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	BALANCE SHEET COMPONENTS The following tables provide details of selected balance sheet components (in thousands): June 29, 2018 December 31, 2017 Accounts receivable, net: Accounts receivable $ 86,253 $ 74,475 Less: allowances for doubtful accounts and sales returns (3,618 ) (4,631 ) Total $ 82,635 $ 69,844 June 29, 2018 December 31, 2017 Prepaid expenses and other current assets: Deferred cost of revenue $ 7,688 $ 4,440 Prepaid maintenance, royalty, rent, property taxes and value added tax 3,753 3,867 Contract assets (1) 2,704 — Capitalized commission 1,293 — Restricted cash (2) 274 530 French R&D tax credits receivable (3) 103 6,609 Other 3,562 3,485 Total $ 19,377 $ 18,931 (1) Contract assets reflect the satisfied performance obligations for which the Company does not yet have an unconditional right to consideration. (2) Amounts represent cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party. (3) The Company’s TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. The amount of R&D tax credits recoverable are subject to audit by the French government. The R&D tax credits receivable at June 29, 2018 were approximately $24.0 million and are expected to be recoverable from 2018 through 2022 with $0.1 million reported as a component of “Prepaid expenses and other current assets” and $23.9 million reported as a component of “Other long-term assets” on the Company’s Condensed Consolidated Balance Sheets. June 29, 2018 December 31, 2017 Inventories: Raw materials $ 1,973 $ 2,881 Work-in-process 755 933 Finished goods 8,871 10,130 Service-related spares 11,395 12,032 Total $ 22,994 $ 25,976 June 29, 2018 December 31, 2017 Property and equipment, net: Machinery and equipment $ 88,129 $ 87,121 Capitalized software 35,527 35,139 Leasehold improvements 14,978 15,051 Furniture and fixtures 6,499 6,534 Property and equipment, gross 145,133 143,845 Less: accumulated depreciation and amortization (119,502 ) (114,580 ) Total $ 25,631 $ 29,265 June 29, 2018 December 31, 2017 Other long-term assets: R&D tax credits receivable $ 23,940 $ 22,322 Deferred tax assets 9,563 10,462 Equity investment 3,771 3,593 Others (1) 5,589 6,536 Total $ 42,863 $ 42,913 (1) As of December 31, 2017, the Company had approximately $1.2 million of restricted cash for the bank guarantee associated with the TVN French Subsidiary’s office building lease. The restriction was subsequently released and accordingly, the amount was reclassified to “Cash and cash equivalents” in the six months ended June 29, 2018 . June 29, 2018 December 31, 2017 Accrued and other current liabilities: Accrued employee compensation and related expenses $ 15,750 $ 16,414 Customer deposits 4,888 5,020 Accrued warranty 4,647 4,381 Contingent inventory reserves 3,700 3,806 Accrued royalty payments 2,583 2,195 Accrued TVN VDP, current (1) 2,446 3,186 Accrued Avid litigation settlement, current 1,500 — Others 15,707 13,703 Total $ 51,221 $ 48,705 (1) See Note 8, “Restructuring and related charges-TVN VDP,” for additional information on the Company’s TVN VDP liabilities.

Goodwill and Identified Intangi

Goodwill and Identified Intangible Assets	6 Months Ended
	Jun. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Identified Intangible Assets	GOODWILL AND IDENTIFIED INTANGIBLE ASSETS Goodwill Goodwill represents the difference between the purchase price and the estimated fair value of the identifiable assets acquired and liabilities assumed. Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. The Company has two reporting units, Video and Cable Access. The Company tests for goodwill impairment at the reporting unit level on an annual basis in the fiscal fourth quarter, or more frequently, if events or changes in circumstances indicate that the asset is more likely than not impaired. The Company performed its annual goodwill impairment review at the reporting unit level as of October 31, 2017, with no goodwill impairment indicated. There were no events or circumstances which triggered additional impairment reviews for the periods presented. The changes in the carrying amount of goodwill by reportable segments for the six months ended June 29, 2018 were as follows (in thousands): Video Cable Access Total Balance as of December 31, 2017 $ 182,012 $ 60,815 $ 242,827 Foreign currency translation adjustment (1,633 ) (18 ) (1,651 ) Balance as of June 29, 2018 $ 180,379 $ 60,797 $ 241,176 Intangible Assets The following is a summary of intangible assets (in thousands): June 29, 2018 December 31, 2017 Weighted Average Remaining Life (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed core technology 1.7 $ 31,707 $ (22,985 ) $ 8,722 $ 31,707 $ (20,396 ) $ 11,311 Customer relationships/contracts 2.7 44,690 (36,664 ) 8,026 44,819 (35,205 ) 9,614 Trademarks and trade names 1.7 630 (368 ) 262 654 (300 ) 354 Maintenance agreements and related relationships n/a 5,500 (5,500 ) — 5,500 (5,500 ) — Order Backlog n/a 3,128 (3,128 ) — 3,177 (3,177 ) — Total identifiable intangibles $ 85,655 $ (68,645 ) $ 17,010 $ 85,857 $ (64,578 ) $ 21,279 Amortization expense for the identifiable purchased intangible assets for the three and six months ended June 29, 2018 and June 30, 2017 was allocated as follows (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Included in cost of revenue $ 1,295 $ 1,295 $ 2,590 $ 2,590 Included in operating expenses 800 780 1,604 1,554 Total amortization expense $ 2,095 $ 2,075 $ 4,194 $ 4,144 The estimated future amortization expense of purchased intangible assets with definite lives is as follows (in thousands): Cost of Revenue Operating Expenses Total Year ended December 31, 2018 (remaining six months) $ 2,590 $ 1,584 $ 4,174 2019 5,180 3,167 8,347 2020 951 3,036 3,987 2021 — 502 502 Total future amortization expense $ 8,721 $ 8,289 $ 17,010

Restructuring and Related Charg

Restructuring and Related Charges	6 Months Ended
	Jun. 29, 2018
Restructuring and Related Activities [Abstract]
Restructuring and Related Charges	RESTRUCTURING AND RELATED CHARGES The Company has implemented several restructuring plans in the past few years. The goal of these plans was to bring operational expenses to appropriate levels relative to its net revenues, while simultaneously implementing extensive company-wide expense control programs. The Company accounts for its restructuring plans under the authoritative guidance for exit or disposal activities. The restructuring and related charges are included in “Cost of revenue” and “Operating expenses - Restructuring and related charges” in the Condensed Consolidated Statements of Operations. The following table summarizes the restructuring and related charges (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Restructuring and related charges in: Cost of revenue $ 115 $ 278 $ 877 $ 786 Operating expenses - Restructuring and related charges 631 777 1,717 2,056 Total restructuring and related charges $ 746 $ 1,055 $ 2,594 $ 2,842 As of June 29, 2018 and December 31, 2017, the Company’s total restructuring liability was $6.1 million and $8.0 million , respectively, of which $3.5 million and $4.4 million , respectively, were reported as a component of “Accrued and other current liabilities”, and the remaining $2.6 million and $3.6 million , respectively, were reported as a component of “Other non-current liabilities” on the Company’s Condensed Consolidated Balance Sheets. Harmonic 2018 Restructuring In the first quarter of 2018, the Company approved and implemented a restructuring plan (the “Harmonic 2018 Restructuring Plan”). The restructuring activities under this plan primarily include worldwide workforce reductions of the Company. As of June 29, 2018 , the Company recorded an aggregate amount of $1.8 million of restructuring and related charges for severance and employee benefits for 55 employees worldwide, primarily in the United States and across all functions. The Company made $1.7 million in payments for this plan in the six months ended June 29, 2018, with the remaining $0.1 million liability outstanding at June 29, 2018 . The activities under this plan are expected to be completed in 2018. Harmonic 2017 Restructuring In the third quarter of 2017, the Company implemented a restructuring plan (the “Harmonic 2017 Restructuring Plan”) to better align its operating costs with the continued decline in its net revenues. In 2017, the Company recorded $2.5 million of restructuring and related charges under this plan, consisting of $2.1 million of employee severance and $0.4 million related to the closure of one of the Company’s offices in New York. The activities under this plan were completed in 2017. As of June 29, 2018 , the remaining $0.2 million liability outstanding relates to the accrual for the New York excess facility, which will be paid out over the remainder of the New York leased property’s term through August 2020. Harmonic 2016 Restructuring In the first quarter of 2016, the Company implemented a restructuring plan (the “Harmonic 2016 Restructuring Plan”) to reduce operating costs by consolidating duplicative resources in connection with the acquisition of Thomson Video Networks (“TVN”). The planned activities included global workforce reductions, exiting certain operating facilities and disposing of excess areas, and an employee voluntary departure plan in France (the “TVN VDP”). In 2016, the Company recorded an aggregate of $20.0 million of restructuring and related charges under the Harmonic 2016 Restructuring Plan, of which $2.2 million was primarily related to the Company exiting from an excess facility at its U.S. headquarters and the remaining $17.8 million was related to severance and benefits for the termination of 118 employees worldwide, including 83 employees in France who participated in the TVN VDP. The restructuring and related charges under the Harmonic 2016 Restructuring Plan in 2016 were partially offset by approximately $2.0 million of gain from TVN pension curtailment. TVN VDP The Company recorded $0.5 million and $1.8 million of TVN VDP costs in the six months ended June 29, 2018 and June 30, 2017, respectively. The TVN VDP liability balance as of June 29, 2018 was $3.8 million , payable from 2018 through 2020. Excess Facility in San Jose, California In January 2016, the Company exited an excess facility at its U.S. headquarters in San Jose, California and recorded $1.4 million of facility exit costs. The fair value of this liability is based on a net present value model using a credit-adjusted risk-free rate. The liability will be paid out over the remainder of the leased properties’ term, which continues through August 2020. As of the cease-use date, the fair value of this restructuring liability totaled $2.5 million . Offsetting this charge was an adjustment for deferred rent liability relating to this space of $1.1 million . As a result of a change in the estimate of the sublease income, the restructuring liability was increased by $1.2 million as of December 31, 2017. The following table summarizes the activity in the Company’s restructuring accrual related to the Harmonic 2016 Restructuring Plan during the six months ended June 29, 2018 (in thousands): Excess facilities TVN VDP (1) Total Balance at December 31, 2017 $ 2,426 $ 5,128 $ 7,554 Adjustments to restructuring provisions 66 477 543 Cash payments (502 ) (1,653 ) (2,155 ) Foreign exchange gain — (107 ) (107 ) Balance at June 29, 2018 1,990 3,845 5,835 Less: current portion (1) (900 ) (2,446 ) (3,346 ) Long-term portion (1) $ 1,090 $ 1,399 $ 2,489 (1) The current portion and long-term portion of the restructuring liability are reported as components of “Accrued and other current liabilities” and “Other non-current liabilities”, respectively, on the Company’s Condensed Consolidated Balance Sheets.

Convertible Notes, Other Debts

Convertible Notes, Other Debts And Capital Leases	6 Months Ended
	Jun. 29, 2018
Debt Disclosure [Abstract]
Convertible Notes, Other Debts And Capital Leases	CONVERTIBLE NOTES, OTHER DEBTS AND CAPITAL LEASES 4.00% Convertible Senior Notes In December 2015, the Company issued $128.25 million in aggregate principal amount of 4.0% unsecured convertible senior notes due December 1, 2020 (the “offering” or “Notes”, as applicable) through a private placement with a financial institution. The Notes do not contain any financial covenants and the Company can settle the Notes in cash, shares of common stock, or any combination thereof. The Notes can be converted under certain circumstances described below, based on an initial conversion rate of 173.9978 shares of common stock per $1,000 principal amount of Notes (which represents an initial conversion price of approximately $5.75 per share). Interest on the Notes is payable semiannually in arrears on June 1 and December 1 of each year. Concurrent with the closing of the offering, the Company used $49.9 million of the net proceeds to repurchase 11.1 million shares of the Company’s common stock from purchasers of the offering in privately negotiated transactions. In addition, the Company incurred approximately $4.1 million in debt issuance costs, resulting in net proceeds to the Company of approximately $74.2 million , which was used to fund the acquisition of our France subsidiary, TVN. Prior to September 1, 2020, holders of the Notes may convert the Notes at their option only under the following circumstances: (1) during any fiscal quarter commencing after the fiscal quarter ending on April 1, 2016, if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price of the Notes on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events. Commencing on September 1, 2020 until the close of business on the second scheduled trading day immediately preceding the maturity date, the Notes will be convertible in multiples of $1,000 principal amount regardless of the foregoing circumstances. If a fundamental change occurs, holders of the Notes may require the Company to purchase all or any portion of their Notes for cash at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, if specific corporate events occur prior to the maturity date, the conversion rate may be increased for a holder who elects to convert the Notes in connection with such a corporate event. In accordance with the accounting guidance on embedded conversion features, the conversion feature associated with the Notes was valued at $26.1 million and bifurcated from the host debt instrument and recorded in stockholders’ equity. The resulting debt discount on the Notes is being amortized to interest expense at the effective interest rate over the contractual term of the Notes. The following table presents the components of the Notes as of June 29, 2018 and December 31, 2017 (in thousands, except for years and percentages): June 29, 2018 December 31, 2017 Liability: Principal amount $ 128,250 $ 128,250 Less: Debt discount, net of amortization (14,767 ) (17,404 ) Less: Debt issuance costs, net of amortization (1,781 ) (2,098 ) Carrying amount $ 111,702 $ 108,748 Remaining amortization period (years) 2.4 2.9 Effective interest rate on liability component 9.94 % 9.94 % Carrying amount of equity component $ 26,062 $ 26,062 The following table presents interest expense recognized for the Notes (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Contractual interest expense $ 1,282 $ 1,282 $ 2,565 $ 2,565 Amortization of debt discount 1,340 1,214 2,637 2,388 Amortization of debt issuance costs 161 146 317 288 Total interest expense recognized $ 2,783 $ 2,642 $ 5,519 $ 5,241 Other Debts and Capital Leases The Company has a variety of debt and credit facilities in France to satisfy the financing requirements of TVN operations. These arrangements are summarized in the table below (in thousands): June 29, 2018 December 31, 2017 Financing from French government agencies related to various government incentive programs (1) $ 14,401 $ 20,565 Term loans 1,081 1,282 Obligations under capital leases 559 1,099 Total debt obligations 16,041 22,946 Less: current portion (1,723 ) (7,610 ) Long-term portion $ 14,318 $ 15,336 (1) As of June 29, 2018 and December 31, 2017, loans backed by French R&D tax credit receivables were $12.0 million and $17.7 million , respectively. As of June 29, 2018 , the TVN French Subsidiary had an aggregate of $24.0 million of R&D tax credit receivables from the French government from 2018 through 2022. See Note 6, “Balance Sheet Components” for additional information. These tax loans have a fixed rate of 0.6% , plus EURIBOR 1 month + 1.3% and mature between 2018 through 2020. The remaining loans of $2.4 million at June 29, 2018 , primarily relate to financial support from French government agencies for R&D innovation projects at minimal interest rates, and these loans mature between 2018 through 2025. Future minimum repayments The table below presents the future minimum repayments of debts and capital lease obligations for TVN as of June 29, 2018 (in thousands): Years ending December 31, Capital lease obligations Other Debt obligations 2018 (remaining six months) $ 395 $ 864 2019 92 6,879 2020 49 6,687 2021 23 497 2022 — 457 Thereafter — 98 Total $ 559 $ 15,482 Line of Credit On September 27, 2017, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (the “Bank”). The Loan Agreement provides for a secured revolving credit facility in an aggregate principal amount of up to $15.0 million . Under the terms of the Loan Agreement, the principal amount of loans, plus the face amount of any outstanding letters of credit, at any time cannot exceed up to 85% of the Company’s eligible receivables. Under the terms of the Loan Agreement, the Company may also request letters of credit from the Bank. The proceeds of any loans under the Loan Agreement will be used for working capital and general corporate purposes. Loans under the Loan Agreement will bear interest, at the Company’s option, and subject to certain conditions, at an annual rate of either a prime rate or a LIBOR rate plus an applicable margin of 2.25% . There will be no applicable margin for prime rate advances when the Company is in compliance with the liquidity requirement of at least $20.0 million in the aggregate of consolidated cash plus availability under the Loan Agreement (the “Liquidity Requirement”) and a 0.25% margin for prime rate advances when the Company is not in compliance with the Liquidity Requirement. The Company may not request LIBOR advances when it is not in compliance with the Liquidity Requirement. Interest on each advance is due and payable monthly and the principal balance is due at maturity. The Company’s obligations under the revolving credit facility are secured by a security interest on substantially all of its assets, excluding intellectual property. The Loan Agreement contains customary affirmative and negative covenants. The Company must comply with financial covenants requiring it to maintain (i) a short-term asset to short-term liabilities ratio of at least 1.10 to 1.00 and (ii) a minimum adjusted EBITDA, in the amounts and for the periods as set forth in the Loan Agreement. The Company must also maintain a minimum liquidity amount, comprised of unrestricted cash held at accounts with the Bank plus proceeds available to be drawn under the Loan Agreement, equal to at least $10.0 million at all times. As of June 29, 2018 , the Company was in compliance with the covenants under the Loan Agreement. As of June 29, 2018, the Company committed $2.4 million towards security for letters of credit issued under the Loan Agreement. There were no other borrowings under the Loan Agreement as of June 29, 2018 .

Employee Benefit Plans and Stoc

Employee Benefit Plans and Stock-based Compensation	6 Months Ended
	Jun. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Benefit Plans and Stock-based compensation	EMPLOYEE BENEFIT PLANS AND STOCK-BASED COMPENSATION Equity Award Plans The Company’s stock benefit plans include the 2002 Employee Stock Purchase Plan (“ESPP”) and current active stock plans adopted in 1995 and 2002. See Note 12, “Employee Benefit Plans and Stock-based Compensation” of Notes to Consolidated Financial Statements in the 2017 Form 10-K for details pertaining to each plan. The Company’s stockholders approved an amendment to the ESPP at the 2018 annual meeting of stockholders (the “2018 Annual Meeting”) to increase the number of shares of common stock reserved for issuance under the ESPP by 1,300,000 shares. The Company’s stockholders also approved an amendment to the 2002 Director Stock Plan at the 2018 Annual Meeting to increase the number of shares of common stock reserved for issuance thereunder by 400,000 shares. As of June 29, 2018 , there were 5.3 million and 1.8 million shares of common stock reserved for future grants under the Company’s ESPP and active stock plans, respectively. Stock Option Activities The following table summarizes the Company’s stock option activities and related information during the six months ended June 29, 2018 (in thousands, except per share amounts and terms): Stock Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balance at December 31, 2017 3,880 $ 6.04 Granted — — Exercised (87 ) 2.94 Forfeited (35 ) 4.76 Canceled or expired (538 ) 8.75 Balance at June 29, 2018 3,220 5.69 2.8 $ 866.8 As of June 29, 2018 Vested and expected to vest 3,208 5.69 2.8 $ 859.3 Exercisable 2,958 5.77 2.7 $ 696.1 The aggregate intrinsic value disclosed above represents the difference between the exercise price of the options and the fair value of the Company’s common stock. There were no employee stock options granted in the six months ended June 29, 2018 . There were no realized tax benefits attributable to stock options exercised in jurisdictions where this expense is deductible for tax purposes for the three and six months ended June 29, 2018 and June 30, 2017 , respectively. Restricted Stock Units (“RSUs”) Activities The following table summarizes the Company’s RSUs activities and related information during the six months ended June 29, 2018 (in thousands, except per share amounts and terms): Restricted Stock Units Outstanding Number Weighted Balance at December 31, 2017 2,904 5.09 Granted 3,293 3.74 Vested (2,220 ) 4.75 Forfeited (183 ) 5.09 Balance at June 29, 2018 3,794 4.12 Performance- and Market-based awards Starting in 2015, the Company began to settle a portion of its incentive bonus payments to eligible employees by issuing performance-based RSU awards (“PRSUs”) from the 1995 Stock Plan. The Company granted 969,598 PRSUs to certain employees for the six months ended June 29, 2018 , of which 869,598 shares of PRSUs were fully vested at the time of grant for purposes of settling amounts earned under the Company’s 2017 incentive bonus plans. The vesting of the remaining PRSUs will be based on the achievement of certain financial and non-financial operating goals of the Company. The stock-based compensation recognized for PRSUs was $0.1 million and $3.4 million for the three and six months ended June 29, 2018 , respectively. The unrecognized stock-based compensation of PRSUs as of June 29, 2018 was $0.3 million . In 2017, the Company granted 344,500 market-based RSUs (“MRSUs”) under the 1995 Stock Plan to its key executives and certain eligible employees that may vest during a three -year period as part of its long-term incentive program. In the second quarter of 2018, the Company granted 40,000 MRSUs that may vest during an eighteen -month period from the date of grant. The vesting conditions of these awards are based on the market value of the Company's common stock. The aggregate grant-date fair value of these shares was estimated to be $1.3 million using a Monte-Carlo simulation. The stock-based compensation recognized for MRSUs for the three and six months ended June 29, 2018 was $0.1 million and $0.2 million , respectively. The unrecognized stock-based compensation of the MRSUs as of June 29, 2018 was $0.1 million . No MRSUs had vested as of June 29, 2018 . French Retirement Benefit Plan The Company assumed obligations under a defined benefit pension plan in connection with the acquisition of TVN in 2016. The plan is unfunded and there are no contributions required by laws or funding regulations, discretionary contributions or non-cash contributions expected to be made. The table below presents the components of net periodic benefit costs (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, June 30, Service cost $ 63 $ 55 $ 126 $ 110 Interest cost 19 16 38 32 Recognized net actuarial loss — 2 — 3 Net periodic benefit cost $ 82 $ 73 $ 164 $ 145 The present value of the Company’s pension obligation as of June 29, 2018 was $5.0 million , of which $0.1 million was reported as a component of “Accrued and other current liabilities” and $4.9 million was reported as a component of “Other non-current liabilities” on the Company’s Condensed Consolidated Balance Sheets. The present value of the Company’s pension obligation as of December 31, 2017 was $5.0 million . 401(k) Plan The Company has a retirement/savings plan for its U.S. employees, which qualifies as a thrift plan under Section 401(k) of the Internal Revenue Code. This plan allows participants to contribute up to the applicable Internal Revenue Code limitations under the plan. The Company has made discretionary contributions to the plan of 25% of the first 4% contributed by eligible participants, up to a maximum contribution per participant of $1,000 per year. The contributions for the six months ended June 29, 2018 and June 30, 2017 were $214,000 and $285,000 , respectively. Stock-based Compensation The following table summarizes stock-based compensation for all plans (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Stock-based compensation in: Cost of revenue $ 448 $ 700 $ 963 $ 1,145 Research and development expense 818 1,337 2,622 2,314 Selling, general and administrative expense 1,746 2,099 5,184 3,928 Total stock-based compensation in operating expense 2,564 3,436 7,806 6,242 Total stock-based compensation $ 3,012 $ 4,136 $ 8,769 $ 7,387 As of June 29, 2018 , total unrecognized stock-based compensation cost related to unvested stock options and RSUs was $13.3 million and is expected to be recognized over a weighted-average period of approximately 1.8 years. Prior to January 1, 2017, stock-based compensation expense was recorded net of estimated forfeitures in the Company’s Condensed Consolidated Statements of Operations and, accordingly, was recorded for only those stock-based awards that the Company expected to vest. Upon the adoption of ASU 2016-09, “Improvements to Employee Share-Based payments” issued by FASB, effective January 1, 2017, the Company changed its accounting policy to account for forfeitures as they occur. The change was applied on a modified retrospective approach with a cumulative effect adjustment of $69,000 as of January 1, 2017 (which increased the accumulated deficit). Valuation Assumptions The Company estimates the fair value of employee stock options and stock purchase rights under the ESPP using a Black-Scholes option valuation model. The value of the stock purchase rights under the ESPP consists of: (1) the 15% discount on the purchase of the stock; (2) 85% of the fair value of the call option; and (3) 15% of the fair value of the put option. The call option and put option were valued using the Black-Scholes option pricing model. At the date of grant, the Company estimated the fair value of each stock option grant and stock purchase right granted under the ESPP using the following weighted average assumptions: Stock Options Three and six months ended June 30, Expected term (years) 4.3 Volatility 43% Risk-free interest rate 1.7% Expected dividends 0.0% ESPP Purchase Period Ending July 2, July 3, Expected term (years) 0.5 0.5 Volatility 60 % 41 % Risk-free interest rate 1.7 % 1.0 % Expected dividends 0.0 % 0.0 % Estimated weighted average fair value per share at purchase date $1.34 $1.40 The expected term of the employee stock options represents the weighted-average period that the stock options are expected to remain outstanding. The computation of the expected term was determined based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and expectations of future employee behavior. The expected term of the stock purchase rights under the ESPP represents the period of time from the beginning of the offering period to the purchase date. The Company uses its historical volatility for a period equivalent to the expected term of the options to estimate the expected volatility. The risk-free interest rate assumption is based on U.S. Treasury zero-coupon issues with remaining terms similar to the expected term. The Company has not paid and does not plan to pay any cash dividends in the foreseeable future.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company reported the following operating results for the periods presented (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Loss before income taxes $ (2,022 ) $ (30,921 ) $ (14,638 ) $ (55,180 ) Provision for income taxes 891 579 1,969 347 Effective income tax rate (44.1 )% (1.9 )% (13.5 )% (0.6 )% The Company operates in multiple jurisdictions and its profits are taxed pursuant to the tax laws of these jurisdictions. The Company’s effective income tax rate may be affected by changes in, or interpretations of tax laws and tax agreements in any given jurisdiction, utilization of net operating loss and tax credit carry forwards, changes in geographical mix of income and expense, and changes in management’s assessment of matters such as the ability to realize deferred tax assets. The Company’s effective tax rate varies from year to year primarily due to the absence of several onetime, discrete items that benefited or decremented the tax rates in the previous years. The Company's effective income tax rate of (13.5)% for the six months ended June 29, 2018 was different from the U.S. federal statutory rate of 21% , primarily due to the Company’s geographical income mix and favorable tax rates associated with certain earnings from operations in lower-tax jurisdictions, the increase in the valuation allowance against U.S. federal, California and other state deferred tax assets, detriment from non-deductible stock-based compensation, and the net of various discrete tax adjustments . For the six months ended June 29, 2018 , the discrete adjustments to the Company's tax expense were primarily withholding taxes. The Company files U.S. federal and state, and foreign income tax returns in jurisdictions with varying statutes of limitations during which such tax returns may be audited and adjusted by the relevant tax authorities. The 2014 through 2017 tax years generally remain subject to examination by U.S. federal and most state tax authorities. In significant foreign jurisdictions, the 2007 through 2017 tax years generally remain subject to examination by their respective tax authorities. If, upon the conclusion of an audit, the ultimate determination of taxes owed in the jurisdictions under audit is for an amount in excess of the tax provision the Company has recorded in the applicable period, the Company’s overall tax expense, effective tax rate, operating results and cash flow could be materially and adversely impacted in the period of adjustment. On July 27, 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner, 145 T.C. No.3 (2015) related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. A final decision was entered by the U.S. Tax Court on December 1, 2015 (the “2015 Decision”). On February 19, 2016, the U.S. Internal Revenue Service filed a notice of appeal in Altera Corp. v. Commissioner , 145 T.C. No. 3 (2015), to the Ninth Circuit Court of Appeals. The Ninth Circuit was to decide whether a regulation that mandates that stock-based compensation costs related to the intangible development activity of a qualified cost sharing arrangement (a “QCSA”) must be included in the joint cost pool of the QCSA (the “all costs rule”) is consistent with the arm’s length standard as set forth in Section 482 of the Internal Revenue Code. On July 24, 2018, the Ninth Circuit Court of Appeals issued an opinion in Altera Corp. v. Commissioner (the “Altera Opinion”) requiring related parties in an intercompany cost-sharing arrangement to share expenses related to share-based compensation. This opinion reversed the 2015 Decision of the United States Tax Court. Due to uncertainties surrounding the ultimate resolution of the 2015 Decision, the Company continued to share expenses related to share-based compensation despite the 2015 Decision. Therefore, the Altera Opinion is not expected to have an impact on the Company’s consolidated financial statements. The Company’s operations in Switzerland are subject to a reduced tax rate under the Switzerland tax holiday which requires various thresholds of investment and employment in Switzerland. The Company has met these various thresholds and the Switzerland tax holiday is effective through the end of 2018. As of June 29, 2018 , the total amount of gross unrecognized tax benefits, including interest and penalties, was approximately $17.9 million , of which $1.1 million would affect the Company’s effective tax rate if the benefits are eventually recognized. The remaining gross unrecognized tax benefit does not affect the Company’s effective tax rate as it relates to positions that would be settled with tax attributes such as net operating loss carryforward or tax credits previously subject to a valuation allowance. The Company recognizes interest and penalties related to unrecognized tax positions in income tax expense. The Company had $0.5 million of gross interest and penalties accrued as of June 29, 2018 . The Company will continue to review its tax positions and provide for, or reverse, unrecognized tax benefits as issues arise. As of June 29, 2018 , the Company released $1.5 million from a 2013-2015 audit settlement in Israel. In March 2016, the FASB issued ASU 2016-09, an accounting standard update for the accounting of share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The new standard eliminated the requirement to report excess tax benefits and certain tax deficiencies related to share-based payment transactions as additional paid-in capital. It also removes the requirement to delay recognition of a windfall tax benefit until it reduces current taxes payable. Under the new guidance, the benefit will be recorded when it arises, subject to normal valuation allowance considerations. The Company adopted this new accounting standard beginning in the first quarter of fiscal 2017 using a modified-retrospective transition method and recorded a cumulative effect of $4.6 million of additional gross deferred tax assets associated with shared-based payments and an offsetting valuation allowance of the same amount, therefore resulting in no net impact to the Company’s beginning retained earnings. In October 2016, the FASB issued ASU 2016-16, an accounting standard update which requires companies to recognize the income tax consequences of all intra-entity sales of assets other than inventory when they occur. As a result, a reporting entity would recognize the tax expense from the sale of the asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. Any deferred tax assets that arise in the buyer’s jurisdiction would also be recognized at the time of the transfer. The Company early adopted this accounting standard update during the first quarter of fiscal 2017 on a modified retrospective approach and recorded a cumulative-effect adjustment of $1.4 million as of January 1, 2017 (which reduced the accumulated deficit). Correspondingly, in the first quarter of fiscal 2017, the Company recognized an additional $1.1 million of net deferred tax assets, after netting with $2.1 million of valuation allowances, and wrote off the remaining $0.3 million of unamortized tax expenses deferred under the previous guidance to provision for income taxes in the first quarter of fiscal 2017.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 29, 2018
Earnings Per Share [Abstract]
Income (Loss) Per Share	NET LOSS PER SHARE The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except per share amounts): Three months ended Six months ended June 29, June 30, June 29, June 30, Numerator: Net loss $ (2,913 ) $ (31,500 ) $ (16,607 ) $ (55,527 ) Denominator: Weighted average number of common shares outstanding Basic and diluted 85,304 80,590 84,616 80,203 Net loss per share: Basic and diluted $ (0.03 ) $ (0.39 ) $ (0.20 ) $ (0.69 ) Basic and diluted net loss per share were the same for the three and six months ended June 29, 2018 and June 30, 2017 , as the inclusion of potential common shares outstanding would have been anti-dilutive due to the Company’s net losses for the periods presented. The following table sets forth the potential weighted common shares outstanding that were excluded from the computation of basic and diluted net loss per share calculations (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Stock options 3,234 4,614 3,469 4,753 RSUs 3,326 3,400 2,766 3,054 Stock purchase rights under the ESPP 541 578 689 385 Warrants (1) 782 782 782 782 Total (2) 7,883 9,374 7,706 8,974 (1) On September 26, 2016, in connection with the execution of a product supply agreement pursuant to which an affiliate of Comcast Corporation (together with Comcast Corporation, “Comcast”) may, in its sole discretion, purchase from the Company licenses to certain of the Company’s software products, the Company granted Comcast a warrant to purchase shares of its common stock. (See Note 13, “Warrants” for additional information). (2) Excluded from the table above are the Notes, which are convertible under certain conditions into an aggregate of 22,304,348 shares of common stock. (See Note 9, “Convertible Notes, Other Debts and Capital Leases” for additional information on the Notes). Since the Company’s intent is to settle the principal amount of the Notes in cash, the treasury stock method is being used to calculate any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread will have a dilutive impact on diluted net income per share when the Company’s average market price of its common stock for a given period exceeds the conversion price of $5.75 per share.

Warrants

Warrants	6 Months Ended
	Jun. 29, 2018
Equity [Abstract]
Warrants Disclosure	WARRANTS On September 26, 2016, the Company issued a Warrant to Comcast pursuant to which Comcast may, subject to certain vesting provisions, purchase up to 7,816,162 shares of the Company’s common stock, subject to adjustment in accordance with the terms of the Warrant, for a per share exercise price of $4.76 . Comcast may exercise the Warrant for cash or on a net share basis. The Warrant expires on September 26, 2023 or the prior consummation of a change of control of the Company. Comcast’s right to purchase 781,617 shares vested as of the issuance date as an incentive to enter into the software license product supply agreement. Comcast’s rights to purchase an additional 1,954,042 shares in specified tranches vest upon achievement of certain milestones that occur upon or prior to Comcast’s election for enterprise license pricing for certain of the Company’s software products. Such pricing would obligate Comcast to make certain total payments to the Company over the term of the product supply agreement. These tranches include the right to purchase 1,172,425 shares upon the acceptance and completion of field trials and 781,617 shares upon the election date, as defined in the Warrant. Comcast’s rights to purchase an additional 1,172,425 shares in specified tranches vest when Comcast exceeds specified cumulative purchase amounts from the Company under the product supply agreement. Comcast’s rights to purchase the remaining shares vest in specified tranches at the earlier of Comcast’s enterprise license pricing election (if completed by a certain date) or achievement of specified cumulative purchase amounts from the Company. Because the Warrant contains performance criteria which Comcast must achieve for the Warrant to vest, the final measurement date for the Warrant is the date on which the Warrant vests. Prior to the final measurement, when achievement of the performance criteria has been deemed probable, the estimated fair value of the Warrant is recorded as a reduction to net revenue based on the projected number of shares underlying the Warrant that are expected to vest, the proportion of purchases by Comcast and its affiliates within the period relative to the aggregate purchase levels required for the Warrant to vest and the then-current fair value of the Warrant. To the extent that projections change as to the number of shares underlying the Warrant that will vest and the fair market value of the Warrant changes, a cumulative catch-up adjustment is recorded in the period in which the estimates change. The fair value of the Warrant is determined using the Black-Scholes option pricing model. The assumptions utilized in the Black-Scholes model include the risk-free interest rate, expected volatility, and expected life in years. The risk-free interest rate over the expected life is equal to the prevailing U.S. Treasury note rate over the same period. Expected volatility is determined utilizing historical volatility over a period of time equal to the expected life of the Warrant. Expected life is equal to the remaining contractual term of the Warrant. The dividend yield is assumed to be zero since the Company has not historically declared dividends and does not have any plans to declare dividends in the future. During the three and six months ended June 29, 2018, the Company recorded $0.3 million and $0.4 million , respectively, as a reduction to net revenues in connection with amortization of warrants. During the six months ended June 30, 2017, the Company recorded reduction to net revenues of $0.4 million in connection with amortization of warrants. No such charges were recorded for the three months ended June 30, 2017. The remaining unamortized value of the related asset of $0.6 million and $1.0 million as of June 29, 2018 and December 31, 2017, respectively, was recorded as a component of “Prepaid expenses and other current assets” on the Company’s Consolidated Balance Sheet.

Segment Information

Segment Information	6 Months Ended
	Jun. 29, 2018
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and evaluated by the Company’s Chief Operating Decision Maker (the “CODM”), which for Harmonic is its Chief Executive Officer, in deciding how to allocate resources and assess performance. Based on our internal reporting structure, the Company consists of two operating segments: Video and Cable Access. The operating segments were determined based on the nature of the products offered. The Video segment sells video processing and production and playout solutions and services worldwide to broadcast and media companies, streaming new media companies, cable operators, and satellite and telecommunications (telco) Pay-TV service providers. The Cable Access segment sells cable access solutions and related services to cable operators globally. The following table provides summary financial information by reportable segment (in thousands): Three months ended Six months ended June 29, 2018 (1) June 30, 2017 June 29, 2018 June 30, 2017 Video Revenue $ 79,208 $ 73,379 $ 150,956 $ 147,721 Gross profit 43,558 37,720 84,784 78,493 Operating income (loss) 6,239 (8,947 ) 8,234 (14,783 ) Cable Access Revenue $ 20,236 $ 8,936 $ 38,726 $ 17,537 Gross profit 10,187 1,699 18,827 3,909 Operating income (loss) 540 (7,411 ) (973 ) (13,491 ) Total Revenue $ 99,444 $ 82,315 $ 189,682 $ 165,258 Gross profit 53,745 39,419 103,611 82,402 Operating income (loss) 6,779 (16,358 ) 7,261 (28,274 ) (1) The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company has prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the three and six months ended June 30, 2017 compared to the Company’s historical approach was an increase in operating loss of $2.1 million and $3.2 million , respectively, from the Video segment and a corresponding decrease in operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments. A reconciliation of the Company’s consolidated segment operating income (loss) to consolidated loss before income taxes is as follows (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Total segment operating income (loss) $ 6,779 $ (16,358 ) $ 7,261 $ (28,274 ) Amortization of warrants (284 ) — (395 ) — Unallocated corporate expenses (746 ) (4,853 ) (2,588 ) (8,775 ) Stock-based compensation (3,012 ) (4,136 ) (8,769 ) (7,387 ) Amortization of intangibles (2,095 ) (2,075 ) (4,194 ) (4,144 ) Income (loss) from operations 642 (27,422 ) (8,685 ) (48,580 ) Non-operating expense, net (2,664 ) (3,499 ) (5,953 ) (6,600 ) Loss before income taxes $ (2,022 ) $ (30,921 ) $ (14,638 ) $ (55,180 ) Unallocated Corporate Expenses Together with amortization of intangibles and stock-based compensation, the Company does not allocate restructuring and related charges, TVN acquisition- and integration-related costs, and certain other non-recurring charges to the operating income (loss) for each segment because management does not include this information in the measurement of the performance of the operating segments. A measure of assets by segment is not applicable as segment assets are not included in the discrete financial information provided to the CODM.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 29, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Leases Future minimum lease payments under non-cancelable operating leases as of June 29, 2018 are as follows (in thousands): Years ending December 31, 2018 (remaining six months) $ 6,505 2019 11,420 2020 8,379 2021 2,907 2022 2,431 Thereafter 10,758 Total $ 42,400 Warranties The Company accrues for estimated warranty costs at the time of product shipment. Management periodically reviews the estimated fair value of its warranty liability and records adjustments based on the terms of warranties provided to customers, historical and anticipated warranty claims experience, and estimates of the timing and cost of warranty claims. Activity for the Company’s warranty accrual, which is included in “Accrued and other current liabilities”, is summarized below (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Balance at beginning of period $ 4,522 $ 4,585 $ 4,381 $ 4,862 Accrual for current period warranties 1,714 1,277 3,450 2,495 Warranty costs incurred (1,589 ) (1,720 ) (3,184 ) (3,215 ) Balance at end of period $ 4,647 $ 4,142 $ 4,647 $ 4,142 Purchase Obligations The Company relies on a limited number of contract manufacturers and suppliers to provide manufacturing services for a substantial majority of its products. Obligations to purchase inventory and other commitments are generally expected to be fulfilled within one year. The Company had approximately $38.7 million of non-cancelable commitments to purchase inventories and other commitments as of June 29, 2018 . Standby Letters of Credit and Guarantees As of June 29, 2018 , the Company has outstanding bank guarantees and standby letters of credit in aggregate of $3.1 million , consisting primarily of $1.3 million for a building lease for the TVN French Subsidiary and $0.8 million related to contract manufacturing, with the remainder mainly related to performance bonds issued to customers. During 2017, one of the Company’s subsidiaries entered into a $2.0 million credit facility with a foreign bank for the purpose of issuing performance guarantees. The credit facility is secured by a $2.2 million guarantee issued by the Company. There were no amounts outstanding under this credit facility as of June 29, 2018 . Indemnification Harmonic is obligated to indemnify its officers and the members of its Board of Directors (the “Board”) pursuant to its bylaws and contractual indemnity agreements. Harmonic also indemnifies some of its suppliers and most of its customers for specified intellectual property matters pursuant to certain contractual arrangements, subject to certain limitations. The scope of these indemnities varies, but, in some instances, includes indemnification for damages and expenses (including reasonable attorneys’ fees). There have been no amounts accrued in respect of these indemnification provisions through June 29, 2018 . Legal proceedings In October 2011, Avid Technology, Inc. (“Avid”) filed a complaint in the United States District Court for the District of Delaware alleging that our MediaGrid product infringes two patents held by Avid. A jury trial on this complaint commenced on January 23, 2014 and, on February 4, 2014, the jury returned a unanimous verdict in favor of us, rejecting Avid’s infringement allegations in their entirety. In January 2015, Avid filed an appeal with respect to the jury’s verdict with the Federal Circuit. In January 2016, the Federal Circuit issued an order vacating the verdict of noninfringement and remanding the case to the trial court for a new trial on infringement. In June 2012, Avid served a subsequent complaint in the United States District Court for the District of Delaware alleging that our Spectrum product infringes one patent held by Avid. The complaint sought injunctive relief and unspecified damages. In September 2013, the U.S. Patent Trial and Appeal Board (“PTAB”) authorized an inter partes review to be instituted as to claims 1-16 of the patent asserted in this second complaint. In July 2014, the PTAB issued a decision finding claims 1-10 invalid and claims 11-16 not invalid. We filed an appeal with respect to the PTAB’s decision on claims 11-16 in September 2014, and the Federal Circuit affirmed the PTAB’s decision in April 2016. In July 2017, the court issued a scheduling order consolidating both cases and setting the trial date for November 6, 2017. On October 19, 2017, the parties agreed to settle the consolidated cases by entering into a settlement and patent portfolio cross-license agreement, and the cases were dismissed with prejudice. In connection with the agreement, the Company recorded a $6.0 million litigation settlement expense in “Selling, general and administrative expenses” in the Company’s 2017 Consolidated Statement of Operations. Of the associated $6.0 million liability, $2.5 million was paid in October 2017 and the remaining $1.5 million and $2.0 million will be paid in the second quarter of 2019 and the third quarter of 2020, respectively. From time to time, the Company is involved in lawsuits as well as subject to various legal proceedings, claims, threats of litigation, and investigations in the ordinary course of business, including claims of alleged infringement of third-party patents and other intellectual property rights, commercial, employment, and other matters. The Company assesses potential liabilities in connection with each lawsuit and threatened lawsuits and accrues an estimated loss for these loss contingencies if both of the following conditions are met: information available prior to issuance of the financial statements indicates that it is probable that a liability has been incurred at the date of the financial statements and the amount of loss can be reasonably estimated. While certain matters to which the Company is a party specify the damages claimed, such claims may not represent reasonably probable losses. Given the inherent uncertainties of litigation, the ultimate outcome of these matters cannot be predicted at this time, nor can the amount of possible loss or range of loss, if any, be reasonably estimated.

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 29, 2018
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT On July 31, 2018, pursuant to the vesting provisions of the Warrant, a tranche of 1,172,425 Warrant shares vested and became exercisable upon the acceptance of completion of field trials by Comcast. The fair value of the Warrant on the date of vesting is estimated to be $2.3 million using the Black-Scholes option pricing model. See Note 13, “Warrants” for additional information.

Basis of Presentation and Sig23

Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 29, 2018
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make 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 revenue and expenses during the reporting period. The Company’s reported financial positions or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information.
Significant Accounting Policies	The Company’s significant accounting policies are described in Note 2 to its audited Consolidated Financial Statements included in the 2017 Form 10-K. There have been no significant changes to these policies during the six months ended June 29, 2018 other than those disclosed in Note 2, “Recently Adopted Accounting Pronouncements”.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Recently Adopted Accounting Pronouncements ASC Topic 606, “Revenue from Contracts with Customers” On January 1, 2018, the Company adopted ASC 606, Revenue from Contracts with Customers (“Topic 606”), using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for the reporting period beginning January 1, 2018 are presented under Topic 606, while prior period amounts are not restated and continue to be reported in accordance with our historic accounting under ASC 605, Revenue Recognition (“Topic 605”). Under Topic 606, the Company began to recognize a contract asset for satisfied performance obligations that do not provide the Company with an unconditional right to consideration, which was restricted under the previous standard. In addition, the Company changed its revenue recognition for professional services from a completed contract method to a percentage of completion method. The cumulative effect of initially applying Topic 606 to the Company’s condensed consolidated balance sheet on January 1, 2018 was as follows (in thousands): CONDENSED CONSOLIDATED BALANCE SHEETS Balance as of December 31, 2017 Cumulative Impact from Adopting Topic 606 Balance as of January 1, 2018 ASSETS Accounts receivable, net $ 69,844 $ 1,781 $ 71,625 Prepaid expenses and other current assets 18,931 3,578 22,509 Other long-term assets 42,913 773 43,686 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue $ 52,429 $ (4,826 ) $ 47,603 Other non-current liabilities 22,626 (473 ) 22,153 Accumulated deficit (2,057,812 ) 11,431 (2,046,381 ) The impact from adopting Topic 606 on the Company’s condensed consolidated financial statements was as follows (in thousands): Three months ended June 29, 2018 Six months ended June 29, 2018 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 As Reported Previous Accounting Guidance Impact from Adopting Topic 606 Total net revenue $ 99,160 $ 98,714 $ 446 $ 189,287 $ 188,037 $ 1,250 Total cost of revenue 47,557 47,316 241 90,501 90,141 360 Total gross profit 51,603 51,398 205 98,786 97,896 890 Operating expenses: Selling, general and administrative 27,988 28,570 (582 ) 59,151 59,541 (390 ) Income (loss) from operations 642 (145 ) 787 (8,685 ) (9,965 ) 1,280 Loss before income taxes (2,022 ) (2,809 ) 787 (14,638 ) (15,918 ) 1,280 Net loss (2,913 ) (3,700 ) 787 (16,607 ) (17,887 ) 1,280 As of June 29, 2018 CONDENSED CONSOLIDATED BALANCE SHEETS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 ASSETS Accounts receivable, net 82,635 78,065 $ 4,570 Prepaid expenses and other current assets 19,377 15,918 3,459 Other long-term assets 42,863 42,360 503 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue 56,278 60,032 (3,754 ) Other non-current liabilities 19,169 19,594 (425 ) Accumulated deficit (2,062,988 ) (2,075,699 ) 12,711 Revenue Recognition The Company’s principal sources of revenue are from the sale of hardware, software, hardware and software maintenance contracts, and end-to-end solutions, encompassing design, manufacture, test, integration and installation of products. The Company also derives recurring revenue from subscriptions, which are comprised of subscription fees from customers utilizing the Company’s cloud-based media processing solutions. Revenue from contracts with customers is recognized using the following five steps: a) Identify the contract(s) with a customer; b) Identify the performance obligations in the contract; c) Determine the transaction price; d) Allocate the transaction price to the performance obligations in the contract; and e) Recognize revenue when (or as) the Company satisfies a performance obligation. A contract contains a promise (or promises) to transfer goods or services to a customer. A performance obligation is a promise (or a group of promises) that is distinct. The transaction price is the amount of consideration a Company expects to be entitled from a customer in exchange for providing the goods or services. The unit of account for revenue recognition is a performance obligation (a good or service). A contract may contain one or more performance obligations. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. Otherwise performance obligations will be combined with other promised goods or services until the Company identifies a bundle of goods or services that is distinct. The transaction price is allocated to all the separate performance obligations in an arrangement. It reflects the amount of consideration to which the Company expects to be entitled in exchange for transferring goods or services, which may include an estimate of variable consideration to the extent that it is probable of not being subject to significant reversals in the future based on the Company’s experience with similar arrangements. The transaction price also reflects the impact of the time value of money if there is a significant financing component present in an arrangement. The transaction price excludes amounts collected on behalf of third parties, such as sales taxes. Revenue is recognized when the Company satisfies each performance obligation by transferring control of the promised goods or services to the customer. Goods or services can transfer at a point in time or over time depending on the nature of the arrangement. Deferred revenue represents the Company’s obligation to transfer goods or services to a customer for which the Company has received consideration (or an amount of consideration is due) from the customer. Our payment terms vary by the type and location of our customer and the products or services offered. The term between invoicing and when payment is due is not significant. For certain products or services and customer types, we require payment before the products or services are delivered to the customer. During the three and six months ended June 29, 2018, the Company recognized $24.1 million and $44.0 million of revenue, respectively, that were included in Deferred revenue at the beginning of each respective period. Contract assets exist when the Company has satisfied a performance obligation but does not have an unconditional right to consideration (e.g., because the entity first must satisfy another performance obligation in the contract before it is entitled to invoice the customer). Contract assets are reported as a component of “Prepaid expenses and other current assets” on the Condensed Consolidated Balance Sheets. See Note 6, “Balance Sheet Components’ for additional information. Shipping and handling costs are accounted for as a fulfillment cost and are recorded in cost of revenue in the Company’s Condensed Consolidated Statements of Operations. Hardware and Software. Revenue from the sale of hardware and software products is recognized when the control is transferred. For most of the Company’s product sales (including sales to distributors and system integrators), the control is transferred at the time the product is shipped or delivery has occurred because the customer has significant risks and rewards of ownership of the asset and the Company has a present right to payment at that time. The Company’s agreements with the distributors and system integrators have terms which are generally consistent with the standard terms and conditions for the sale of the Company’s equipment to end users, and do not provide for product rotation or pricing allowances, as are typically found in agreements with stocking distributors. We offer trade-in rights which are specifically identified and accrued for at the end of the period through contra-revenue. Arrangements with Multiple Performance Obligations. The Company has revenue arrangements that include multiple performance obligations. The Company allocates transaction price to all separate performance obligations based on their relative standalone selling prices (“SSP”). The Company’s best evidence for SSP is the price the Company charges for that good or service when the Company sells it separately in similar circumstances to similar customers. If goods or services are not always sold separately, the Company uses the best estimate of SSP in the allocation of transaction price. The objective of determining the best estimate of SSP is to estimate the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The Company’s process for determining best estimate of SSP involves management’s judgment, and considers multiple factors including, but not limited to, major product groupings, geographies, gross margin objectives and pricing practices. Pricing practices taken into consideration include contractually stated prices, discounts offered and applicable price lists. These factors may vary over time, depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change or should future facts and circumstances lead the Company to consider additional factors, the Company’s best estimate of SSP may also change. Solution Sales. Solution sales for the design, manufacture, test, integration and installation of products, including equipment acquired from third parties to be integrated with Harmonic’s products, that are customized to meet the customer’s specifications are accounted for based on the percentage-of-completion basis, using the input method. Some of our arrangements may include acceptance provisions that require testing of the solution against specific performance criteria. The Company performs a detailed evaluation to determine whether the arrangement involves performance criteria based on our standard performance criteria. The Company has a long-standing history of entering into contractual arrangements to deliver the solution sales based on standard performance criteria. For this type of arrangement, we consider the customer acceptance clause not substantive and recognize product revenue when the customer takes possession on the product and recognize service on a percentage-of-completion basis. However, if the solution results in significant production, modification or customization, we consider the arrangement as a single performance obligation and recognize the revenue at a point in time, depending on the complexity of the solution and nature of acceptance. Professional services. Revenue from professional services is recognized over time, on the percentage-of-completion basis using the input method. Input method. The use of the input method requires the Company to make reasonably dependable estimates. We use the input method based on labor hours, where revenue is calculated based on the percentage of total hours incurred in relation to total estimated hours at completion of the contract. The input method is reasonable because the hours best reflect the Company’s efforts toward satisfying the performance obligation over time. As circumstances change over time, the Company updates its measure of progress to reflect any changes in the outcome of the performance obligation. Such changes to an entity’s measure of progress are accounted for as a change in accounting estimates. Support and maintenance. Support and maintenance services are satisfied ratably over time as the customer simultaneously receives and consumes the benefits of the services. As a result, support and maintenance revenue is recognized on a straight line basis over the period of the contract. Contract costs . The incremental costs of obtaining a contract are capitalized if the costs are expected to be recovered. Costs that are recognized as assets are amortized straight-line over the period as the related goods or services transfer to the customer. Costs incurred to fulfill a contract are capitalized if they are not covered by other relevant guidance, relate directly to a contract, will be used to satisfy future performance obligations, and are expected to be recovered. The Company recorded a net decrease to the opening balance of accumulated deficit of $1.4 million as of January 1, 2018 for capitalizing contract costs due to the cumulative impact of adopting Topic 606 for sales commissions related to customer contracts with an amortization period in excess of one year. Anticipated contract renewals, amendments, and follow-on contracts with the same customer are considered when determining the period of amortization. The net capitalized contract costs as of June 29, 2018 were $1.8 million , of which $1.3 million and $ 0.5 million were reported as components of “Prepaid expenses and other current assets” and “Other long-term assets” on the Condensed Consolidated Balance Sheets, respectively. The amortization of the capitalized contract costs during the three and six months ended June 29, 2018 was $0.3 million and $0.5 million , respectively. Significant Judgments . The Company has revenue arrangements that include promises to transfer multiple products and services to a customer. The Company may exercise significant judgment when determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together. The Company allocates the transaction price to all separate performance obligations based on the SSP of each obligation. The Company’s best evidence for SSP is the price the Company charges for that good or service when the Company sells it separately in similar circumstances to similar customers. If goods or services are not always sold separately, the Company uses the best estimate of SSP in the allocation of the transaction price. The objective of determining the best estimate of SSP is to estimate the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The Company’s process for determining the best estimate of SSP involves management’s judgment, and considers multiple factors including, but not limited to, major product groupings, geographies, gross margin objectives and pricing practices. Pricing practices taken into consideration include contractually stated prices, discounts and applicable price lists. These factors may vary over time, depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change or should future facts and circumstances lead the Company to consider additional factors, the Company’s best estimate of SSP may also change. Practical Expedients and Exemptions. Under Topic 606, incremental costs of obtaining a contract such as sales commissions are capitalized if they are expected to be recovered, and amortized on a straight-line basis. Expensing these costs as incurred is not permitted unless they qualify for a practical expedient. Other than capitalized costs of obtaining subscription contracts which are amortized regardless of the life of expected amortization period, the Company elected the practical expedient to expense the costs to obtain all other contracts as incurred, when the life of the expected amortization period is one year or less by using a portfolio approach. The Company elected the practical expedient under Topic 606 to not disclose the transaction price allocated to remaining performance obligations, since the majority of the Company’s arrangements have original expected durations of one year or less, or the invoicing corresponds to the value of the Company’s performance completed to date. The Company elected the practical expedient that allows the Company to not assess a contract for a significant financing component if the period between the customer’s payment and the transfer of the goods or services is one year or less. See Note 14, “Segment Information” for further disaggregated revenue information. Other Recently Adopted Accounting Pronouncements In January 2016, the Financial Accounting Standards Board (“FASB) issued Accounting Standards Updated (“ASU”) No. 2016-01, Financial Instruments (Topic 825): Recognition and Measurement of Financial Assets and Financial Liabilities, which requires equity investments to be measured at fair value with changes in fair value recognized in net income and simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. The Company adopted this new standard in the first quarter of fiscal 2018, and the adoption did not have a material impact on its condensed consolidated financial statements. See Note 3, “Investments in Equity Securities” for additional information. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, which requires entities to present the aggregate changes in cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, the statement of cash flows will be required to present restricted cash and restricted cash equivalents as a part of the beginning and ending balances of cash and cash equivalents. The Company adopted this new standard in the first quarter of fiscal 2018 on a retrospective basis. The Company’s total restricted cash balance was $0.3 million and $1.7 million as of June 29, 2018 and December 31, 2017, respectively. The Company’s total restricted cash balance was $1.9 million and $1.8 million as of June 30, 2017 and December 31, 2016, respectively. These restricted cash balances are presented as a part of the ending and beginning balances of cash, cash equivalents and restricted cash on the Company’s Condensed Consolidated Statements of Cash Flows for the corresponding periods. See Note 6, “Balance Sheet Components” for additional information. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The objective of ASU 2017-01 is to clarify the definition of a business in order to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The Company adopted this new standard in the first quarter of fiscal 2018, and the adoption had no impact on its condensed consolidated financial statements. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), to amend the existing accounting standard for lease accounting. Under this guidance, lessees and lessors should apply a “right-of-use” model in accounting for all leases (including subleases) and eliminate the concept of operating leases and off-balance sheet leases. The new leases standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2019 and early adoption is permitted. The Company will be required to recognize the right-of-use assets and liabilities of operating leases upon adoption of the new guidance. The Company continues to evaluate the effect of adopting this guidance on its consolidated financial statements and related disclosures. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which amends ASC Topic 842 to provide another transition method, allowing a cumulative effect adjustment to the opening balance of retained earnings during the period of adoption. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets and certain other instruments. For trade receivables and other instruments, the Company will be required to use a new forward-looking “expected loss” model. Additionally, credit losses on available-for-sale debt securities should be recorded through an allowance for credit losses limited to the amount by which fair value is below amortized cost. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2020 and early adoption is permitted. The adoption of the new ASU is not expected to have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The new ASU removes Step 2 of the goodwill impairment test and requires the assessment of fair value of individual assets and liabilities of a reporting unit to measure goodwill impairments. Goodwill impairment will then be the amount by which a reporting unit's carrying value exceeds its fair value. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2020 on a prospective basis, and early adoption is permitted. The Company is currently evaluating the impact of adopting the new ASU on its consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The new ASU expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should apply the requirements of Topic 718 to nonemployee awards except for specific guidance on inputs to an option pricing model and the attribution of cost. The new ASU will be effective for the Company beginning in the first quarter of fiscal 2019 and early adoption is permitted. The adoption of the new ASU is not expected to have a material impact on the Company’s consolidated financial statements.
Revenue Recognition, Policy	Revenue Recognition The Company’s principal sources of revenue are from the sale of hardware, software, hardware and software maintenance contracts, and end-to-end solutions, encompassing design, manufacture, test, integration and installation of products. The Company also derives recurring revenue from subscriptions, which are comprised of subscription fees from customers utilizing the Company’s cloud-based media processing solutions. Revenue from contracts with customers is recognized using the following five steps: a) Identify the contract(s) with a customer; b) Identify the performance obligations in the contract; c) Determine the transaction price; d) Allocate the transaction price to the performance obligations in the contract; and e) Recognize revenue when (or as) the Company satisfies a performance obligation. A contract contains a promise (or promises) to transfer goods or services to a customer. A performance obligation is a promise (or a group of promises) that is distinct. The transaction price is the amount of consideration a Company expects to be entitled from a customer in exchange for providing the goods or services. The unit of account for revenue recognition is a performance obligation (a good or service). A contract may contain one or more performance obligations. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. Otherwise performance obligations will be combined with other promised goods or services until the Company identifies a bundle of goods or services that is distinct. The transaction price is allocated to all the separate performance obligations in an arrangement. It reflects the amount of consideration to which the Company expects to be entitled in exchange for transferring goods or services, which may include an estimate of variable consideration to the extent that it is probable of not being subject to significant reversals in the future based on the Company’s experience with similar arrangements. The transaction price also reflects the impact of the time value of money if there is a significant financing component present in an arrangement. The transaction price excludes amounts collected on behalf of third parties, such as sales taxes. Revenue is recognized when the Company satisfies each performance obligation by transferring control of the promised goods or services to the customer. Goods or services can transfer at a point in time or over time depending on the nature of the arrangement. Deferred revenue represents the Company’s obligation to transfer goods or services to a customer for which the Company has received consideration (or an amount of consideration is due) from the customer. Our payment terms vary by the type and location of our customer and the products or services offered. The term between invoicing and when payment is due is not significant. For certain products or services and customer types, we require payment before the products or services are delivered to the customer. During the three and six months ended June 29, 2018, the Company recognized $24.1 million and $44.0 million of revenue, respectively, that were included in Deferred revenue at the beginning of each respective period. Contract assets exist when the Company has satisfied a performance obligation but does not have an unconditional right to consideration (e.g., because the entity first must satisfy another performance obligation in the contract before it is entitled to invoice the customer). Contract assets are reported as a component of “Prepaid expenses and other current assets” on the Condensed Consolidated Balance Sheets. See Note 6, “Balance Sheet Components’ for additional information. Shipping and handling costs are accounted for as a fulfillment cost and are recorded in cost of revenue in the Company’s Condensed Consolidated Statements of Operations. Hardware and Software. Revenue from the sale of hardware and software products is recognized when the control is transferred. For most of the Company’s product sales (including sales to distributors and system integrators), the control is transferred at the time the product is shipped or delivery has occurred because the customer has significant risks and rewards of ownership of the asset and the Company has a present right to payment at that time. The Company’s agreements with the distributors and system integrators have terms which are generally consistent with the standard terms and conditions for the sale of the Company’s equipment to end users, and do not provide for product rotation or pricing allowances, as are typically found in agreements with stocking distributors. We offer trade-in rights which are specifically identified and accrued for at the end of the period through contra-revenue.
Revenue Recognition, Multiple-deliverable Arrangements	Arrangements with Multiple Performance Obligations. The Company has revenue arrangements that include multiple performance obligations. The Company allocates transaction price to all separate performance obligations based on their relative standalone selling prices (“SSP”). The Company’s best evidence for SSP is the price the Company charges for that good or service when the Company sells it separately in similar circumstances to similar customers. If goods or services are not always sold separately, the Company uses the best estimate of SSP in the allocation of transaction price. The objective of determining the best estimate of SSP is to estimate the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The Company’s process for determining best estimate of SSP involves management’s judgment, and considers multiple factors including, but not limited to, major product groupings, geographies, gross margin objectives and pricing practices. Pricing practices taken into consideration include contractually stated prices, discounts offered and applicable price lists. These factors may vary over time, depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change or should future facts and circumstances lead the Company to consider additional factors, the Company’s best estimate of SSP may also change. Solution Sales. Solution sales for the design, manufacture, test, integration and installation of products, including equipment acquired from third parties to be integrated with Harmonic’s products, that are customized to meet the customer’s specifications are accounted for based on the percentage-of-completion basis, using the input method. Some of our arrangements may include acceptance provisions that require testing of the solution against specific performance criteria. The Company performs a detailed evaluation to determine whether the arrangement involves performance criteria based on our standard performance criteria. The Company has a long-standing history of entering into contractual arrangements to deliver the solution sales based on standard performance criteria. For this type of arrangement, we consider the customer acceptance clause not substantive and recognize product revenue when the customer takes possession on the product and recognize service on a percentage-of-completion basis. However, if the solution results in significant production, modification or customization, we consider the arrangement as a single performance obligation and recognize the revenue at a point in time, depending on the complexity of the solution and nature of acceptance. Professional services. Revenue from professional services is recognized over time, on the percentage-of-completion basis using the input method. Input method. The use of the input method requires the Company to make reasonably dependable estimates. We use the input method based on labor hours, where revenue is calculated based on the percentage of total hours incurred in relation to total estimated hours at completion of the contract. The input method is reasonable because the hours best reflect the Company’s efforts toward satisfying the performance obligation over time. As circumstances change over time, the Company updates its measure of progress to reflect any changes in the outcome of the performance obligation. Such changes to an entity’s measure of progress are accounted for as a change in accounting estimates. Support and maintenance. Support and maintenance services are satisfied ratably over time as the customer simultaneously receives and consumes the benefits of the services. As a result, support and maintenance revenue is recognized on a straight line basis over the period of the contract. Contract costs . The incremental costs of obtaining a contract are capitalized if the costs are expected to be recovered. Costs that are recognized as assets are amortized straight-line over the period as the related goods or services transfer to the customer. Costs incurred to fulfill a contract are capitalized if they are not covered by other relevant guidance, relate directly to a contract, will be used to satisfy future performance obligations, and are expected to be recovered.
Derivatives and Hedging Activities	The Company uses forward contracts to manage exposures to foreign currency exchange rates. The Company’s primary objective in holding derivative instruments is to reduce the volatility of earnings and cash flows associated with fluctuations in foreign currency exchange rates and the Company does not use derivative instruments for trading purposes. The use of derivative instruments exposes the Company to credit risk to the extent that the counterparties may be unable to meet their contractual obligations. As such, the potential risk of loss with any one counterparty is closely monitored by the Company. Derivatives Not Designated as Hedging Instruments (Balance Sheet Hedges) The Company’s balance sheet hedges consist of foreign currency forward contracts that generally mature within three months, are carried at fair value, and are used to minimize the short-term impact of foreign currency exchange rate fluctuation on cash and certain trade and inter-company receivables and payables. Changes in the fair value of these foreign currency forward contracts are recognized in “Other income (expense), net” in the Condensed Consolidated Statement of Operations and are largely offset by the changes in the fair value of the assets or liabilities being hedged. Offsetting of Derivative Assets and Liabilities The Company recognizes all derivative instruments on a gross basis in the Condensed Consolidated Balance Sheets. However, the arrangements with its counterparties allows for net settlement, which are designed to reduce credit risk by permitting net settlement with the same counterparty.
Fair Value of Financial Instruments	The Company uses the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. The fair value of the Company’s convertible notes is influenced by interest rates, the Company’s stock price and stock market volatility. The authoritative accounting guidance establishes a framework for measuring fair value and requires disclosure about the fair value measurements of assets and liabilities. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, in the principal or most advantageous market for the asset or liability, in an orderly transaction between market participants on the measurement date. This guidance requires the Company to classify and disclose assets and liabilities measured at fair value on a recurring basis, as well as fair value measurements of assets and liabilities measured on a nonrecurring basis in periods subsequent to initial measurement, in a three-tier fair value hierarchy as described below. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The guidance describes three levels of inputs that may be used to measure fair value: • Level 1 — Observable inputs that reflect quoted prices for identical assets or liabilities in active markets. • Level 2 — Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, 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. The forward exchange contracts are classified as Level 2 because they are valued using quoted market prices and other observable data for similar instruments in an active market. • 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.
Goodwill and Intangible Assets, Goodwill	Goodwill represents the difference between the purchase price and the estimated fair value of the identifiable assets acquired and liabilities assumed. Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. The Company has two reporting units, Video and Cable Access. The Company tests for goodwill impairment at the reporting unit level on an annual basis in the fiscal fourth quarter, or more frequently, if events or changes in circumstances indicate that the asset is more likely than not impaired. The Company performed its annual goodwill impairment review at the reporting unit level as of October 31, 2017, with no goodwill impairment indicated. There were no events or circumstances which triggered additional impairment reviews for the periods presented.
Restructuring and Related Charges	The fair value of this liability is based on a net present value model using a credit-adjusted risk-free rate. The liability will be paid out over the remainder of the leased properties’ term, which continues through August 2020.
Share-based Compensation Expense	The Company estimates the fair value of employee stock options and stock purchase rights under the ESPP using a Black-Scholes option valuation model. The value of the stock purchase rights under the ESPP consists of: (1) the 15% discount on the purchase of the stock; (2) 85% of the fair value of the call option; and (3) 15% of the fair value of the put option. The call option and put option were valued using the Black-Scholes option pricing model. The expected term of the employee stock options represents the weighted-average period that the stock options are expected to remain outstanding. The computation of the expected term was determined based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and expectations of future employee behavior. The expected term of the stock purchase rights under the ESPP represents the period of time from the beginning of the offering period to the purchase date. The Company uses its historical volatility for a period equivalent to the expected term of the options to estimate the expected volatility. The risk-free interest rate assumption is based on U.S. Treasury zero-coupon issues with remaining terms similar to the expected term. The Company has not paid and does not plan to pay any cash dividends in the foreseeable future.
Segment Information	Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and evaluated by the Company’s Chief Operating Decision Maker (the “CODM”), which for Harmonic is its Chief Executive Officer, in deciding how to allocate resources and assess performance. Based on our internal reporting structure, the Company consists of two operating segments: Video and Cable Access. The operating segments were determined based on the nature of the products offered. The Video segment sells video processing and production and playout solutions and services worldwide to broadcast and media companies, streaming new media companies, cable operators, and satellite and telecommunications (telco) Pay-TV service providers. The Cable Access segment sells cable access solutions and related services to cable operators globally.
Warranties and Indemnification	The Company accrues for estimated warranty costs at the time of product shipment. Management periodically reviews the estimated fair value of its warranty liability and records adjustments based on the terms of warranties provided to customers, historical and anticipated warranty claims experience, and estimates of the timing and cost of warranty claims. Harmonic is obligated to indemnify its officers and the members of its Board of Directors (the “Board”) pursuant to its bylaws and contractual indemnity agreements. Harmonic also indemnifies some of its suppliers and most of its customers for specified intellectual property matters pursuant to certain contractual arrangements, subject to certain limitations. The scope of these indemnities varies, but, in some instances, includes indemnification for damages and expenses (including reasonable attorneys’ fees).

Recent Accounting Pronounceme24

Recent Accounting Pronouncements - Revenue From Contracts With Customer (Tables)	6 Months Ended
	Jun. 29, 2018
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The cumulative effect of initially applying Topic 606 to the Company’s condensed consolidated balance sheet on January 1, 2018 was as follows (in thousands): CONDENSED CONSOLIDATED BALANCE SHEETS Balance as of December 31, 2017 Cumulative Impact from Adopting Topic 606 Balance as of January 1, 2018 ASSETS Accounts receivable, net $ 69,844 $ 1,781 $ 71,625 Prepaid expenses and other current assets 18,931 3,578 22,509 Other long-term assets 42,913 773 43,686 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue $ 52,429 $ (4,826 ) $ 47,603 Other non-current liabilities 22,626 (473 ) 22,153 Accumulated deficit (2,057,812 ) 11,431 (2,046,381 ) The impact from adopting Topic 606 on the Company’s condensed consolidated financial statements was as follows (in thousands): Three months ended June 29, 2018 Six months ended June 29, 2018 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 As Reported Previous Accounting Guidance Impact from Adopting Topic 606 Total net revenue $ 99,160 $ 98,714 $ 446 $ 189,287 $ 188,037 $ 1,250 Total cost of revenue 47,557 47,316 241 90,501 90,141 360 Total gross profit 51,603 51,398 205 98,786 97,896 890 Operating expenses: Selling, general and administrative 27,988 28,570 (582 ) 59,151 59,541 (390 ) Income (loss) from operations 642 (145 ) 787 (8,685 ) (9,965 ) 1,280 Loss before income taxes (2,022 ) (2,809 ) 787 (14,638 ) (15,918 ) 1,280 Net loss (2,913 ) (3,700 ) 787 (16,607 ) (17,887 ) 1,280 As of June 29, 2018 CONDENSED CONSOLIDATED BALANCE SHEETS As Reported Previous Accounting Guidance Impact from Adopting Topic 606 ASSETS Accounts receivable, net 82,635 78,065 $ 4,570 Prepaid expenses and other current assets 19,377 15,918 3,459 Other long-term assets 42,863 42,360 503 LIABILITIES AND STOCKHOLDERS’ EQUITY Deferred revenue 56,278 60,032 (3,754 ) Other non-current liabilities 19,169 19,594 (425 ) Accumulated deficit (2,062,988 ) (2,075,699 ) 12,711

Derivative and Hedging Activiti

Derivative and Hedging Activities (Tables)	6 Months Ended
	Jun. 29, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments gain and losses by Statement of Operations locations	Losses on the non-designated derivative instruments recognized during the periods presented were as follows (in thousands): Three months ended Six months ended Financial Statement Location June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Derivatives not designated as hedging instruments: Losses recognized in income Other income (expense), net $ (1,268 ) $ (53 ) $ (1,382 ) $ (185 )
Schedule of Notional Amounts of Outstanding Derivative Positions	The U.S. dollar equivalents of all outstanding notional amounts of foreign currency forward contracts, including the Euro, British pound, Israeli shekel and Japanese yen, are summarized as follows (in thousands): June 29, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Purchase $ 24,743 $ 12,875 Sell $ 1,658 $ 1,509
Schedule of Derivatives Instruments Balance Sheet Location	The locations and fair value amounts of the Company’s derivative instruments reported in its Condensed Consolidated Balance Sheets are as follows (in thousands): Asset Derivatives Derivative Liabilities Balance Sheet Location June 29, 2018 December 31, 2017 Balance Sheet Location June 29, 2018 December 31, 2017 Derivatives not designated as hedging instruments: Foreign currency contracts Prepaid expenses and other current assets $ 14 $ 33 Accrued and other current liabilities $ 298 $ 4 Total derivatives $ 14 $ 33 $ 298 $ 4
Changes in fair values of non-designated foreign currency forward contracts	As of June 29, 2018 , information related to the offsetting arrangements was as follows (in thousands): Gross Amounts of Derivatives Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Derivatives Gross Amounts of Derivatives Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivatives Presented in the Condensed Consolidated Balance Sheets Financial Instrument Net Amount Derivative assets $ 14 — $ 14 $ (14 ) $ — Derivative liabilities $ 298 — $ 298 $ (14 ) $ 284

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 29, 2018
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value Based on Three-Tier Fair Value Hierarchy	The following table sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): Level 1 Level 2 Level 3 Total As of June 29, 2018 Cash equivalents Money market funds $ — $ — $ — $ — Derivative assets — 14 — 14 Other long-term assets Long-term investment 178 — — 178 Total assets measured and recorded at fair value $ 178 $ 14 $ — $ 192 Accrued and other current liabilities Derivative liabilities $ — $ 298 $ — $ 298 Total liabilities measured and recorded at fair value $ — $ 298 $ — $ 298 Level 1 Level 2 Level 3 Total As of December 31, 2017 Cash equivalents Money market funds $ 22 $ — $ — $ 22 Prepaid expenses and other current assets Derivative assets — 33 — 33 Total assets measured and recorded at fair value $ 22 $ 33 $ — $ 55 Accrued and other current liabilities Derivative liabilities $ — $ 4 $ — $ 4 Total liabilities measured and recorded at fair value $ — $ 4 $ — $ 4

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts Receivable, Net	The following tables provide details of selected balance sheet components (in thousands): June 29, 2018 December 31, 2017 Accounts receivable, net: Accounts receivable $ 86,253 $ 74,475 Less: allowances for doubtful accounts and sales returns (3,618 ) (4,631 ) Total $ 82,635 $ 69,844
Prepaid, and Other Current Assets	June 29, 2018 December 31, 2017 Prepaid expenses and other current assets: Deferred cost of revenue $ 7,688 $ 4,440 Prepaid maintenance, royalty, rent, property taxes and value added tax 3,753 3,867 Contract assets (1) 2,704 — Capitalized commission 1,293 — Restricted cash (2) 274 530 French R&D tax credits receivable (3) 103 6,609 Other 3,562 3,485 Total $ 19,377 $ 18,931 (1) Contract assets reflect the satisfied performance obligations for which the Company does not yet have an unconditional right to consideration. (2) Amounts represent cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party. (3) The Company’s TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. The amount of R&D tax credits recoverable are subject to audit by the French government. The R&D tax credits receivable at June 29, 2018 were approximately $24.0 million and are expected to be recoverable from 2018 through 2022 with $0.1 million reported as a component of “Prepaid expenses and other current assets” and $23.9 million reported as a component of “Other long-term assets” on the Company’s Condensed Consolidated Balance Sheets.
Inventories	June 29, 2018 December 31, 2017 Inventories: Raw materials $ 1,973 $ 2,881 Work-in-process 755 933 Finished goods 8,871 10,130 Service-related spares 11,395 12,032 Total $ 22,994 $ 25,976
Property, Plant and Equipment	June 29, 2018 December 31, 2017 Property and equipment, net: Machinery and equipment $ 88,129 $ 87,121 Capitalized software 35,527 35,139 Leasehold improvements 14,978 15,051 Furniture and fixtures 6,499 6,534 Property and equipment, gross 145,133 143,845 Less: accumulated depreciation and amortization (119,502 ) (114,580 ) Total $ 25,631 $ 29,265
Other Long Term Assets	June 29, 2018 December 31, 2017 Other long-term assets: R&D tax credits receivable $ 23,940 $ 22,322 Deferred tax assets 9,563 10,462 Equity investment 3,771 3,593 Others (1) 5,589 6,536 Total $ 42,863 $ 42,913
Accrued Liabilities	June 29, 2018 December 31, 2017 Accrued and other current liabilities: Accrued employee compensation and related expenses $ 15,750 $ 16,414 Customer deposits 4,888 5,020 Accrued warranty 4,647 4,381 Contingent inventory reserves 3,700 3,806 Accrued royalty payments 2,583 2,195 Accrued TVN VDP, current (1) 2,446 3,186 Accrued Avid litigation settlement, current 1,500 — Others 15,707 13,703 Total $ 51,221 $ 48,705 (1) See Note 8, “Restructuring and related charges-TVN VDP,” for additional information on the Company’s TVN VDP liabilities.

Goodwill and Identified Intan28

Goodwill and Identified Intangible Assets (Tables)	6 Months Ended
	Jun. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill by reportable segments for the six months ended June 29, 2018 were as follows (in thousands): Video Cable Access Total Balance as of December 31, 2017 $ 182,012 $ 60,815 $ 242,827 Foreign currency translation adjustment (1,633 ) (18 ) (1,651 ) Balance as of June 29, 2018 $ 180,379 $ 60,797 $ 241,176
Summary of Goodwill and Identified Intangible Assets	The following is a summary of intangible assets (in thousands): June 29, 2018 December 31, 2017 Weighted Average Remaining Life (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed core technology 1.7 $ 31,707 $ (22,985 ) $ 8,722 $ 31,707 $ (20,396 ) $ 11,311 Customer relationships/contracts 2.7 44,690 (36,664 ) 8,026 44,819 (35,205 ) 9,614 Trademarks and trade names 1.7 630 (368 ) 262 654 (300 ) 354 Maintenance agreements and related relationships n/a 5,500 (5,500 ) — 5,500 (5,500 ) — Order Backlog n/a 3,128 (3,128 ) — 3,177 (3,177 ) — Total identifiable intangibles $ 85,655 $ (68,645 ) $ 17,010 $ 85,857 $ (64,578 ) $ 21,279
Amortization Expense for Identifiable Purchased Intangible Assets	Amortization expense for the identifiable purchased intangible assets for the three and six months ended June 29, 2018 and June 30, 2017 was allocated as follows (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Included in cost of revenue $ 1,295 $ 1,295 $ 2,590 $ 2,590 Included in operating expenses 800 780 1,604 1,554 Total amortization expense $ 2,095 $ 2,075 $ 4,194 $ 4,144
Estimated Future Amortization Expense of Purchased Intangible Assets	The estimated future amortization expense of purchased intangible assets with definite lives is as follows (in thousands): Cost of Revenue Operating Expenses Total Year ended December 31, 2018 (remaining six months) $ 2,590 $ 1,584 $ 4,174 2019 5,180 3,167 8,347 2020 951 3,036 3,987 2021 — 502 502 Total future amortization expense $ 8,721 $ 8,289 $ 17,010

Restructuring and Related Cha29

Restructuring and Related Charges (Tables)	6 Months Ended
	Jun. 29, 2018
Restructuring Cost and Reserve [Line Items]
Summary of restructuring activities	The following table summarizes the restructuring and related charges (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Restructuring and related charges in: Cost of revenue $ 115 $ 278 $ 877 $ 786 Operating expenses - Restructuring and related charges 631 777 1,717 2,056 Total restructuring and related charges $ 746 $ 1,055 $ 2,594 $ 2,842
Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Schedule of Restructuring Reserve by Type of Cost	The following table summarizes the activity in the Company’s restructuring accrual related to the Harmonic 2016 Restructuring Plan during the six months ended June 29, 2018 (in thousands): Excess facilities TVN VDP (1) Total Balance at December 31, 2017 $ 2,426 $ 5,128 $ 7,554 Adjustments to restructuring provisions 66 477 543 Cash payments (502 ) (1,653 ) (2,155 ) Foreign exchange gain — (107 ) (107 ) Balance at June 29, 2018 1,990 3,845 5,835 Less: current portion (1) (900 ) (2,446 ) (3,346 ) Long-term portion (1) $ 1,090 $ 1,399 $ 2,489 (1) The current portion and long-term portion of the restructuring liability are reported as components of “Accrued and other current liabilities” and “Other non-current liabilities”, respectively, on the Company’s Condensed Consolidated Balance Sheets.

Convertible Notes, Other Debt30

Convertible Notes, Other Debts And Capital Leases (Tables)	6 Months Ended
	Jun. 29, 2018
Debt Disclosure [Abstract]
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	The following table presents the components of the Notes as of June 29, 2018 and December 31, 2017 (in thousands, except for years and percentages): June 29, 2018 December 31, 2017 Liability: Principal amount $ 128,250 $ 128,250 Less: Debt discount, net of amortization (14,767 ) (17,404 ) Less: Debt issuance costs, net of amortization (1,781 ) (2,098 ) Carrying amount $ 111,702 $ 108,748 Remaining amortization period (years) 2.4 2.9 Effective interest rate on liability component 9.94 % 9.94 % Carrying amount of equity component $ 26,062 $ 26,062
Convertible Debt Interest	The following table presents interest expense recognized for the Notes (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Contractual interest expense $ 1,282 $ 1,282 $ 2,565 $ 2,565 Amortization of debt discount 1,340 1,214 2,637 2,388 Amortization of debt issuance costs 161 146 317 288 Total interest expense recognized $ 2,783 $ 2,642 $ 5,519 $ 5,241
Schedule of Other Debt and Capital Leases	he Company has a variety of debt and credit facilities in France to satisfy the financing requirements of TVN operations. These arrangements are summarized in the table below (in thousands): June 29, 2018 December 31, 2017 Financing from French government agencies related to various government incentive programs (1) $ 14,401 $ 20,565 Term loans 1,081 1,282 Obligations under capital leases 559 1,099 Total debt obligations 16,041 22,946 Less: current portion (1,723 ) (7,610 ) Long-term portion $ 14,318 $ 15,336 (1) As of June 29, 2018 and December 31, 2017, loans backed by French R&D tax credit receivables were $12.0 million and $17.7 million , respectively. As of June 29, 2018 , the TVN French Subsidiary had an aggregate of $24.0 million of R&D tax credit receivables from the French government from 2018 through 2022. See Note 6, “Balance Sheet Components” for additional information. These tax loans have a fixed rate of 0.6% , plus EURIBOR 1 month + 1.3% and mature between 2018 through 2020. The remaining loans of $2.4 million at June 29, 2018 , primarily relate to financial support from French government agencies for R&D innovation projects at minimal interest rates, and these loans mature between 2018 through 2025.
Schedule of Maturities of Long-term Debt	The table below presents the future minimum repayments of debts and capital lease obligations for TVN as of June 29, 2018 (in thousands): Years ending December 31, Capital lease obligations Other Debt obligations 2018 (remaining six months) $ 395 $ 864 2019 92 6,879 2020 49 6,687 2021 23 497 2022 — 457 Thereafter — 98 Total $ 559 $ 15,482

Employee Benefit Plans and St31

Employee Benefit Plans and Stock-based Compensation (Tables)	6 Months Ended
	Jun. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Options Outstanding	The following table summarizes the Company’s stock option activities and related information during the six months ended June 29, 2018 (in thousands, except per share amounts and terms): Stock Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balance at December 31, 2017 3,880 $ 6.04 Granted — — Exercised (87 ) 2.94 Forfeited (35 ) 4.76 Canceled or expired (538 ) 8.75 Balance at June 29, 2018 3,220 5.69 2.8 $ 866.8 As of June 29, 2018 Vested and expected to vest 3,208 5.69 2.8 $ 859.3 Exercisable 2,958 5.77 2.7 $ 696.1
Summary of Restricted Stock Units Outstanding	The following table summarizes the Company’s RSUs activities and related information during the six months ended June 29, 2018 (in thousands, except per share amounts and terms): Restricted Stock Units Outstanding Number Weighted Balance at December 31, 2017 2,904 5.09 Granted 3,293 3.74 Vested (2,220 ) 4.75 Forfeited (183 ) 5.09 Balance at June 29, 2018 3,794 4.12
Schedule of Defined Benefit Plans Obligations	The table below presents the components of net periodic benefit costs (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, June 30, Service cost $ 63 $ 55 $ 126 $ 110 Interest cost 19 16 38 32 Recognized net actuarial loss — 2 — 3 Net periodic benefit cost $ 82 $ 73 $ 164 $ 145
Summary of Stock-Based Compensation Expense	Stock-based Compensation The following table summarizes stock-based compensation for all plans (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Stock-based compensation in: Cost of revenue $ 448 $ 700 $ 963 $ 1,145 Research and development expense 818 1,337 2,622 2,314 Selling, general and administrative expense 1,746 2,099 5,184 3,928 Total stock-based compensation in operating expense 2,564 3,436 7,806 6,242 Total stock-based compensation $ 3,012 $ 4,136 $ 8,769 $ 7,387
Valuation Assumptions for Stock Options	Stock Options Three and six months ended June 30, Expected term (years) 4.3 Volatility 43% Risk-free interest rate 1.7% Expected dividends 0.0%
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	ESPP Purchase Period Ending July 2, July 3, Expected term (years) 0.5 0.5 Volatility 60 % 41 % Risk-free interest rate 1.7 % 1.0 % Expected dividends 0.0 % 0.0 % Estimated weighted average fair value per share at purchase date $1.34 $1.40

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 29, 2018
Income Tax Disclosure [Abstract]
Schedule of income before income tax	The Company reported the following operating results for the periods presented (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Loss before income taxes $ (2,022 ) $ (30,921 ) $ (14,638 ) $ (55,180 ) Provision for income taxes 891 579 1,969 347 Effective income tax rate (44.1 )% (1.9 )% (13.5 )% (0.6 )%

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 29, 2018
Earnings Per Share [Abstract]
Numerators and Denominators of Basic and Diluted Net Income (Loss) Per Share Computations	The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except per share amounts): Three months ended Six months ended June 29, June 30, June 29, June 30, Numerator: Net loss $ (2,913 ) $ (31,500 ) $ (16,607 ) $ (55,527 ) Denominator: Weighted average number of common shares outstanding Basic and diluted 85,304 80,590 84,616 80,203 Net loss per share: Basic and diluted $ (0.03 ) $ (0.39 ) $ (0.20 ) $ (0.69 )
Anti-dilutive Securities	The following table sets forth the potential weighted common shares outstanding that were excluded from the computation of basic and diluted net loss per share calculations (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Stock options 3,234 4,614 3,469 4,753 RSUs 3,326 3,400 2,766 3,054 Stock purchase rights under the ESPP 541 578 689 385 Warrants (1) 782 782 782 782 Total (2) 7,883 9,374 7,706 8,974

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 29, 2018
Segment Reporting [Abstract]
Segment Reporting Information, by Segment	The following table provides summary financial information by reportable segment (in thousands): Three months ended Six months ended June 29, 2018 (1) June 30, 2017 June 29, 2018 June 30, 2017 Video Revenue $ 79,208 $ 73,379 $ 150,956 $ 147,721 Gross profit 43,558 37,720 84,784 78,493 Operating income (loss) 6,239 (8,947 ) 8,234 (14,783 ) Cable Access Revenue $ 20,236 $ 8,936 $ 38,726 $ 17,537 Gross profit 10,187 1,699 18,827 3,909 Operating income (loss) 540 (7,411 ) (973 ) (13,491 ) Total Revenue $ 99,444 $ 82,315 $ 189,682 $ 165,258 Gross profit 53,745 39,419 103,611 82,402 Operating income (loss) 6,779 (16,358 ) 7,261 (28,274 ) (1) The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company has prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the three and six months ended June 30, 2017 compared to the Company’s historical approach was an increase in operating loss of $2.1 million and $3.2 million , respectively, from the Video segment and a corresponding decrease in operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments. A reconciliation of the Company’s consolidated segment operating income (loss) to consolidated loss before income taxes is as follows (in thousands): Three months ended Six months ended June 29, 2018 June 30, 2017 June 29, 2018 June 30, 2017 Total segment operating income (loss) $ 6,779 $ (16,358 ) $ 7,261 $ (28,274 ) Amortization of warrants (284 ) — (395 ) — Unallocated corporate expenses (746 ) (4,853 ) (2,588 ) (8,775 ) Stock-based compensation (3,012 ) (4,136 ) (8,769 ) (7,387 ) Amortization of intangibles (2,095 ) (2,075 ) (4,194 ) (4,144 ) Income (loss) from operations 642 (27,422 ) (8,685 ) (48,580 ) Non-operating expense, net (2,664 ) (3,499 ) (5,953 ) (6,600 ) Loss before income taxes $ (2,022 ) $ (30,921 ) $ (14,638 ) $ (55,180 ) Unallocated Corporate Expenses Together with amortization of intangibles and stock-based compensation, the Company does not allocate restructuring and related charges, TVN acquisition- and integration-related costs, and certain other non-recurring charges to the operating income (loss) for each segment because management does not include this information in the measurement of the performance of the operating segments. A measure of assets by segment is not applicable as segment assets are not included in the discrete financial information provided to the CODM.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 29, 2018
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 29, 2018 are as follows (in thousands): Years ending December 31, 2018 (remaining six months) $ 6,505 2019 11,420 2020 8,379 2021 2,907 2022 2,431 Thereafter 10,758 Total $ 42,400
Summary of Warranty Accrual Included in Accrued Liabilities	Activity for the Company’s warranty accrual, which is included in “Accrued and other current liabilities”, is summarized below (in thousands): Three months ended Six months ended June 29, June 30, June 29, June 30, Balance at beginning of period $ 4,522 $ 4,585 $ 4,381 $ 4,862 Accrual for current period warranties 1,714 1,277 3,450 2,495 Warranty costs incurred (1,589 ) (1,720 ) (3,184 ) (3,215 ) Balance at end of period $ 4,647 $ 4,142 $ 4,647 $ 4,142

Recent Accounting Pronounceme36

Recent Accounting Pronouncements - Revenue From Contracts With Customers Beginning Balance Sheet Impact (Details) - USD ($) $ in Thousands	Jun. 29, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 82,635		$ 69,844
Prepaid expenses and other current assets	19,377		18,931
Other long-term assets	42,863		42,913
Deferred revenue	56,278		52,429
Other non-current liabilities	19,169		22,626
Accumulated deficit	(2,062,988)		$ (2,057,812)
Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		$ 71,625
Prepaid expenses and other current assets		22,509
Other long-term assets		43,686
Deferred revenue		47,603
Other non-current liabilities		22,153
Accumulated deficit		(2,046,381)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	78,065
Prepaid expenses and other current assets	15,918
Other long-term assets	42,360
Deferred revenue	60,032
Other non-current liabilities	19,594
Accumulated deficit	(2,075,699)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	4,570	1,781
Prepaid expenses and other current assets	3,459	3,578
Other long-term assets	503	773
Deferred revenue	(3,754)	(4,826)
Other non-current liabilities	(425)	(473)
Accumulated deficit	$ 12,711	$ 11,431

Recent Accounting Pronounceme37

Recent Accounting Pronouncements - Revenue From Contracts With Customers, Financial Statement Impact (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total net revenue	$ 99,160	$ 82,315	$ 189,287	$ 165,258
Total cost of revenue	47,557	48,500	90,501	91,035
Gross Profit	51,603	33,815	98,786	74,223
Selling, general and administrative	27,988	32,625	59,151	67,256
Loss from operations	642	(27,422)	(8,685)	(48,580)
Loss before income taxes	(2,022)	(30,921)	(14,638)	(55,180)
Net loss	(2,913)	$ (31,500)	(16,607)	$ (55,527)
Accounts receivable, net	82,635		82,635			$ 69,844
Prepaid expenses and other current assets	19,377		19,377			18,931
Other long-term assets	42,863		42,863			42,913
Deferred revenue	56,278		56,278			52,429
Other non-current liabilities	19,169		19,169			22,626
Accumulated deficit	(2,062,988)		(2,062,988)			$ (2,057,812)
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net					$ 71,625
Prepaid expenses and other current assets					22,509
Other long-term assets					43,686
Deferred revenue					47,603
Other non-current liabilities					22,153
Accumulated deficit					(2,046,381)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total net revenue	98,714		188,037
Total cost of revenue	47,316		90,141
Gross Profit	51,398		97,896
Selling, general and administrative	28,570		59,541
Loss from operations	(145)		(9,965)
Loss before income taxes	(2,809)		(15,918)
Net loss	(3,700)		(17,887)
Accounts receivable, net	78,065		78,065
Prepaid expenses and other current assets	15,918		15,918
Other long-term assets	42,360		42,360
Deferred revenue	60,032		60,032
Other non-current liabilities	19,594		19,594
Accumulated deficit	(2,075,699)		(2,075,699)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total net revenue	446		1,250
Total cost of revenue	241		360
Gross Profit	205		890
Selling, general and administrative	(582)		(390)
Loss from operations	787		1,280
Loss before income taxes	787		1,280
Net loss	787		1,280
Accounts receivable, net	4,570		4,570		1,781
Prepaid expenses and other current assets	3,459		3,459		3,578
Other long-term assets	503		503		773
Deferred revenue	(3,754)		(3,754)		(4,826)
Other non-current liabilities	(425)		(425)		(473)
Accumulated deficit	$ 12,711		$ 12,711		$ 11,431

Recent Accounting Pronounceme38

Recent Accounting Pronouncements - Narratives (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 29, 2018	Jun. 29, 2018	Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Revenue, Revenue Recognized	$ 24,100	$ 44,000
Accumulated deficit	(2,062,988)	(2,062,988)		$ (2,057,812)
Net Capitalized Contract Costs	1,800	1,800
Capitalized Contract Cost, Amortization	300	500
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit			$ (2,046,381)
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	12,711	12,711	11,431
Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted Cash	300	300		$ 1,700	$ 1,900	$ 1,800
Prepaid Expenses and Other Current Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Capitalized Contract Costs	1,300	1,300
Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Capitalized Contract Costs	$ 500	$ 500
Sales Commission Contract Costs [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit			$ 1,400

Investments in Equity Securit39

Investments in Equity Securities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 29, 2018	Jun. 29, 2018	Oct. 22, 2014	Sep. 02, 2014
Vislink plc [Member]
Schedule of Cost-method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent				3.30%
Cost Method Investments Original Cost				$ 3.3
Pebble Beach Systems [Member]
Schedule of Cost-method Investments [Line Items]
Gain on Change in Fair Value of Cost Investment	$ 0.2	$ 0.2
Variable Interest Entity, Not Primary Beneficiary [Member] | EDC [Member]
Schedule of Cost-method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent			18.40%
Cost Method Investments Original Cost			$ 3.5
Cost-method Investments, Other than Temporary Impairment		$ 0

Derivatives and Hedging Activit

Derivatives and Hedging Activities - Additional Information (Details) $ in Millions	6 Months Ended
	Jun. 29, 2018USD ($)
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Derivative, Term of Contract	3 months
Israel [Member]
Derivative [Line Items]
Compensating Balance, Amount	$ 1

Derivative and Hedging Activi41

Derivative and Hedging Activities gain losses in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Other Nonoperating Income (Expense) [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Losses recognized in income	$ (1,268)	$ (53)	$ (1,382)	$ (185)

Derivatives and Hedging Activ42

Derivatives and Hedging Activities Notional Amounts (Details) - Foreign Exchange Forward [Member] - Not Designated as Hedging Instrument [Member] - Fair Value Hedging [Member] - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Long [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative Asset, Notional Amount	$ 24,743	$ 12,875
Short [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative Liability, Notional Amount	$ 1,658	$ 1,509

Derivatives and Hedging Activ43

Derivatives and Hedging Activities Assets Liabilities Balance Sheet Location (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	$ 14	$ 33
Derivative Liability, Current	298	4
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	14	33
Not Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Current	$ 298	$ 4

Derivatives and Hedging Activ44

Derivatives and Hedging Activities Asset and Liability Offset (Details) $ in Thousands	Jun. 29, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Asset, Gross Amounts of Derivatives	$ 14
Derivative Assets, Gross Amounts of Derivatives Offset in the Condensed Consolidated Balance Sheets	0
Net Amounts of Derivative Assets Presented in the Condensed Consolidated Balance Sheets	14
Derivative Liabilities, Gross Amounts of Derivatives	298
Derivative Liabilities, Gross Amounts of Derivatives Offset in the Condensed Consolidated Balance Sheets	0
Net Amounts of Derivatives Liability Presented in the Condensed Consolidated Balance Sheets	298
Financial Instrument Liability	(14)
Derivative Asset Net Amount	0
Financial Instrument Asset	(14)
Derivative Liability Net Amount	$ 284

Fair Value Measurements - Narra

Fair Value Measurements - Narratives (Details) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Debts, Excluding Capital Leases	$ 15,482
Assets, Fair Value Disclosure, Nonrecurring	0
Liabilities, Fair Value Disclosure, Nonrecurring	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Debt, Fair Value Disclosures	133,600	$ 129,900
Other Debts, Excluding Capital Leases	15,500	21,800
TVN [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Postemployment Benefits Liability	$ 3,400	$ 5,100

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value Based on Three-Tier Fair Value Hierarchy (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	$ 192	$ 55
Total liabilities measured and recorded at fair value	298	4
Cost-method Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	178
Money market funds [Member] | Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value		22
Foreign exchange forward contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	14	33
Foreign exchange forward contracts [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	298	4
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	178	22
Total liabilities measured and recorded at fair value	0	0
Level 1 [Member] | Cost-method Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	178
Level 1 [Member] | Money market funds [Member] | Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value		22
Level 1 [Member] | Foreign exchange forward contracts [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	14	33
Total liabilities measured and recorded at fair value	298	4
Level 2 [Member] | Foreign exchange forward contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	14	33
Level 2 [Member] | Foreign exchange forward contracts [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	298	4
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0	0
Total liabilities measured and recorded at fair value	$ 0	0
Level 3 [Member] | Foreign exchange forward contracts [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value		$ 0

Balance Sheet Components - Acco

Balance Sheet Components - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Receivables [Abstract]
Accounts receivable	$ 86,253	$ 74,475
Less: allowances for doubtful accounts and sales returns	(3,618)	(4,631)
Accounts Receivable, Net, Current	$ 82,635	$ 69,844

Balance Sheet Components - Prep

Balance Sheet Components - Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands		Jun. 29, 2018		Dec. 31, 2017		Jun. 30, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred cost of revenue		$ 7,688		$ 4,440
Prepaid maintenance, royalty, rent, property taxes and value added tax		3,753		3,867
Contract assets(1)	[1]	2,704
Capitalized commission		1,293
Restricted cash(2)		274	[2]	530	[2]	$ 802
French R&D tax credits receivable(3)	[3]	103		6,609
Other		3,562		3,485
Prepaid Expense and Other Assets, Current		$ 19,377		$ 18,931
[1]	Contract assets reflect the satisfied performance obligations for which the Company does not yet have an unconditional right to consideration.
[2]	Amounts represent cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party.
[3]	The Company’s TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. The amount of R&D tax credits recoverable are subject to audit by the French government. The R&D tax credits receivable at June 29, 2018 were approximately $24.0 million and are expected to be recoverable from 2018 through 2022 with $0.1 million reported as a component of “Prepaid expenses and other current assets” and $23.9 million reported as a component of “Other long-term assets” on the Company’s Condensed Consolidated Balance Sheets.

Balance Sheet Components Additi

Balance Sheet Components Additional Information (Details) - USD ($) $ in Thousands		Jun. 29, 2018	Dec. 31, 2017	Jun. 30, 2017
Restricted Cash for bank guarantee		$ 0	$ 1,203	$ 1,142
R&D tax credits receivable		23,940	22,322
French R&D tax credits receivable(3)	[1]	103	$ 6,609
TVN [Member] | Research Tax Credit Carryforward [Member]
R&D tax credits receivable		24,000
Prepaid Expenses and Other Current Assets [Member] | TVN [Member] | Research Tax Credit Carryforward [Member]
French R&D tax credits receivable(3)		100
Other Noncurrent Assets [Member] | TVN [Member] | Research Tax Credit Carryforward [Member]
French R&D tax credits receivable(3)		$ 23,900
[1]	The Company’s TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. The amount of R&D tax credits recoverable are subject to audit by the French government. The R&D tax credits receivable at June 29, 2018 were approximately $24.0 million and are expected to be recoverable from 2018 through 2022 with $0.1 million reported as a component of “Prepaid expenses and other current assets” and $23.9 million reported as a component of “Other long-term assets” on the Company’s Condensed Consolidated Balance Sheets.

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 1,973	$ 2,881
Work-in-process	755	933
Finished goods	8,871	10,130
Service-related spares	11,395	12,032
Inventory, Net	$ 22,994	$ 25,976

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 145,133	$ 143,845
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(119,502)	(114,580)
Property, Plant and Equipment, Net	25,631	29,265
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	88,129	87,121
Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	35,527	35,139
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,978	15,051
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 6,499	$ 6,534

Balance Sheet Components - Othe

Balance Sheet Components - Other Long Term Assets (Details) - USD ($) $ in Thousands		Jun. 29, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
R&D tax credits receivable		$ 23,940	$ 22,322
Deferred tax assets		9,563	10,462
Equity investment		3,771	3,593
Others1	[1]	5,589	6,536
Other Assets, Noncurrent		$ 42,863	$ 42,913
[1]	As of December 31, 2017, the Company had approximately $1.2 million of restricted cash for the bank guarantee associated with the TVN French Subsidiary’s office building lease. The restriction was subsequently released and accordingly, the amount was reclassified to “Cash and cash equivalents” in the six months ended June 29, 2018.

Balance Sheet Components - Accr

Balance Sheet Components - Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands		Jun. 29, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued employee compensation and related expenses		$ 15,750	$ 16,414
Customer deposits		4,888	5,020
Accrued warranty		4,647	4,381
Contingent inventory reserves		3,700	3,806
Accrued royalty payments		2,583	2,195
Accrued TVN VDP, current(1)	[1]	2,446	3,186
Accrued Avid litigation settlement, current		1,500
Others		15,707	13,703
Accrued Liabilities, Current		$ 51,221	$ 48,705
[1]	See Note 8, “Restructuring and related charges-TVN VDP,” for additional information on the Company’s TVN VDP liabilities.

Goodwill and Intangible Assets

Goodwill and Intangible Assets - Narratives (Details)	Oct. 31, 2017USD ($)	Jun. 29, 2018ReportingUnit
Goodwill [Line Items]
Number of Reporting Units | ReportingUnit		2
Goodwill, Impairment Loss | $	$ 0

Goodwill and Identified Intan55

Goodwill and Identified Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 29, 2018USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 242,827
Foreign currency translation adjustment	(1,651)
Balance at end of period	241,176
Video [Member]
Goodwill [Line Items]
Balance at beginning of period	182,012
Foreign currency translation adjustment	(1,633)
Balance at end of period	180,379
Cable Access [Member]
Goodwill [Line Items]
Balance at beginning of period	60,815
Foreign currency translation adjustment	(18)
Balance at end of period	$ 60,797

Goodwill and Identified Intan56

Goodwill and Identified Intangible Assets - Summary of Goodwill and Identified Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 85,655	$ 85,857
Accumulated Amortization	(68,645)	(64,578)
Total future amortization expense	$ 17,010	21,279
Developed Core Technology
Finite-Lived Intangible Assets [Line Items]
Useful Life	1 year 8 months 12 days
Gross Carrying Amount	$ 31,707	31,707
Accumulated Amortization	(22,985)	(20,396)
Total future amortization expense	$ 8,722	11,311
Customer relationships/contracts
Finite-Lived Intangible Assets [Line Items]
Useful Life	2 years 8 months 12 days
Gross Carrying Amount	$ 44,690	44,819
Accumulated Amortization	(36,664)	(35,205)
Total future amortization expense	$ 8,026	9,614
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Useful Life	1 year 8 months 12 days
Gross Carrying Amount	$ 630	654
Accumulated Amortization	(368)	(300)
Total future amortization expense	262	354
Maintenance Agreements and Related Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,500	5,500
Accumulated Amortization	(5,500)	(5,500)
Total future amortization expense	0	0
Order Backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,128	3,177
Accumulated Amortization	(3,128)	(3,177)
Total future amortization expense	$ 0	$ 0

Goodwill and Identified Intan57

Goodwill and Identified Intangible Assets - Amortization Expense for Identifiable Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Included in cost of revenue	$ 1,295	$ 1,295	$ 2,590	$ 2,590
Included in operating expenses	800	780	1,604	1,554
Total amortization expense	$ 2,095	$ 2,075	$ 4,194	$ 4,144

Goodwill and Identified Intan58

Goodwill and Identified Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	$ 4,174
2,019	8,347
2,020	3,987
2,021	502
Total future amortization expense	17,010	$ 21,279
Cost of Sales [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	2,590
2,019	5,180
2,020	951
2,021	0
Total future amortization expense	8,721
Operating Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	1,584
2,019	3,167
2,020	3,036
2,021	502
Total future amortization expense	$ 8,289

Restructuring and Related Cha59

Restructuring and Related Charges Restructuring and Related Charges, COS & OPEX (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Restructuring and Related Activities [Abstract]
Production Related Impairments or Charges	$ 115	$ 278	$ 877	$ 786
Restructuring and related charges	631	777	1,717	2,056
Restructuring Charges	$ 746	$ 1,055	$ 2,594	$ 2,842

Restructuring and Related Cha60

Restructuring and Related Charges - Additional Information (Detail) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
		Jan. 31, 2016USD ($)	Jun. 29, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 29, 2018USD ($)Employees	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)Employees	Jan. 04, 2016USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve			$ 6,100		$ 6,100		$ 8,000
Restructuring Reserve, Current			3,500		3,500		4,400
Restructuring Reserve, Noncurrent			2,600		2,600		3,600
Adjustments to restructuring provisions			631	$ 777	1,717	$ 2,056
Harmonic 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost							2,500
Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve			5,835		5,835		7,554
Restructuring Reserve, Current	[1]		3,346		3,346
Restructuring Reserve, Noncurrent	[1]		2,489		2,489
Restructuring and Related Cost, Incurred Cost								$ 20,000
Payments for Restructuring					2,155
Adjustments to restructuring provisions					543
Facility Closing [Member] | Harmonic 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Noncurrent			200		200
Restructuring and Related Cost, Incurred Cost							400
Facility Closing [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve			1,990		1,990		2,426
Restructuring Reserve, Current	[1]		900		900
Restructuring Reserve, Noncurrent	[1]		1,090		1,090
Restructuring and Related Cost, Incurred Cost								2,200
Payments for Restructuring					502
Adjustments to restructuring provisions					66
Employee Severance And Benefit Arrangements [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost								$ 17,800
Number of positions eliminated | Employees								118
Employee Severance [Member] | Harmonic 2018 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Current			100		100
Restructuring and Related Cost, Incurred Cost					$ 1,800
Number of positions eliminated | Employees					55
Payments for Restructuring					$ 1,700
Employee Severance [Member] | Harmonic 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost							2,100
TVN Voluntary Departure Plan [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve			3,845		3,845		5,128
Restructuring Reserve, Current	[1]		2,446		2,446
Restructuring Reserve, Noncurrent	[1]		1,399		1,399
Payments for Restructuring					1,653
Adjustments to restructuring provisions					477
TVN [Member]
Restructuring Cost and Reserve [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment								$ 2,000
Postemployment Benefits Liability			3,400		3,400		5,100
TVN [Member] | Employee Severance And Benefit Arrangements [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | Employees								83
TVN [Member] | TVN Voluntary Departure Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges					500	$ 1,800
Postemployment Benefits Liability			$ 3,800		$ 3,800
San Jose CA Excess Facility [Member] | Facility Closing [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 1,400
Fair Value of Excess Facility Restructuring									$ 2,500
Deferred Rent Credit									$ 1,100
Adjustments to restructuring provisions							$ 1,200
[1]	The current portion and long-term portion of the restructuring liability are reported as components of “Accrued and other current liabilities” and “Other non-current liabilities”, respectively, on the Company’s Condensed Consolidated Balance Sheets.

Restructuring and Related Cha61

Restructuring and Related Charges - 2016 Activities in Restructuring Accrual (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Production Related Impairments or Charges		$ 115	$ 278	$ 877	$ 786
Restructuring Reserve [Roll Forward]
Beginning Balance				8,000
Restructuring and related charges		631	$ 777	1,717	$ 2,056
Ending Balance		6,100		8,000		$ 8,000
Restructuring Reserve, Current		(3,500)				(4,400)
Restructuring Reserve, Noncurrent		2,600				3,600
Harmonic 2016 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance				7,554
Restructuring and related charges				543
Cash payments				(2,155)
Foreign exchange gain (loss)				(107)
Ending Balance		5,835		7,554		7,554
Restructuring Reserve, Current	[1]	(3,346)
Restructuring Reserve, Noncurrent	[1]	2,489
Harmonic 2016 Restructuring Plan [Member] | Facility Closing [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance				2,426
Restructuring and related charges				66
Cash payments				(502)
Ending Balance		1,990		2,426		2,426
Restructuring Reserve, Current	[1]	(900)
Restructuring Reserve, Noncurrent	[1]	1,090
Harmonic 2016 Restructuring Plan [Member] | TVN Voluntary Departure Plan [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance				5,128
Restructuring and related charges				477
Cash payments				(1,653)
Foreign exchange gain (loss)				(107)
Ending Balance		3,845		$ 5,128		$ 5,128
Restructuring Reserve, Current	[1]	(2,446)
Restructuring Reserve, Noncurrent	[1]	$ 1,399
[1]	The current portion and long-term portion of the restructuring liability are reported as components of “Accrued and other current liabilities” and “Other non-current liabilities”, respectively, on the Company’s Condensed Consolidated Balance Sheets.

Convertible Notes, Other Debt62

Convertible Notes, Other Debts And Capital Leases - Additional Information (Detail) $ / shares in Units, shares in Millions		Dec. 14, 2015shares	Jun. 29, 2018USD ($)$ / shares	Jun. 29, 2018USD ($)$ / shares	Dec. 31, 2015USD ($)day$ / shares	Dec. 31, 2017USD ($)	Jun. 30, 2017$ / shares
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					4.00%
Debt Instrument, Face Amount			$ 128,250,000	$ 128,250,000	$ 128,250,000	$ 128,250,000
Debt Instrument, Convertible, Conversion Ratio					173.9978
Debt Conversion, Converted Instrument, Amount					$ 1,000
Debt Instrument, Convertible, Conversion Price | $ / shares			$ 5.75	$ 5.75	$ 5.75		$ 5.75
Debt Issuance Cost, Gross, Noncurrent					$ 4,100,000
Percentage Of Principal Amount Of Convertible Notes Is Equal To Repurchase Price					100.00%
Term loans			$ 1,081,000	$ 1,081,000		1,282,000
Financing from French government agencies related to various government incentive programs (1)	[1]		14,401,000	14,401,000		20,565,000
Carrying amount of equity component			26,062,000	26,062,000		26,062,000
Stock price greater or equal 130 percent of Note Conversion Price [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days | day					20
Debt Instrument, Convertible, Threshold Consecutive Trading Days | day					30
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger					130.00%
Note price less than 98 percent of stock price times conversion rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days | day					5
Debt Instrument, Convertible, Threshold Consecutive Trading Days | day					5
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger					98.00%
Privately Negotiated Transactions [Member]
Debt Instrument [Line Items]
Proceeds from Convertible Debt					$ 49,900,000
Stock Repurchased and Retired During Period, Shares | shares		11.1
TVN [Member]
Debt Instrument [Line Items]
Proceeds from Convertible Debt					$ 74,200,000
Income Taxes Receivable			$ 24,000,000	$ 24,000,000
Loans Backed By French Research And Development Tax Credit Receivables [Member] | TVN [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			0.60%	0.60%
Adjusted EURIBOR Rate, Term			1 month
Debt Instrument, Basis Spread on Variable Rate			1.30%
Financing from French government agencies related to various government incentive programs (1)	[1]		$ 12,000,000	$ 12,000,000		$ 17,700,000
Loans From French Government For R&D Innovation Projects [Member]
Debt Instrument [Line Items]
Financing from French government agencies related to various government incentive programs (1)	[1]		2,400,000	2,400,000
Revolving Credit Facility [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity			15,000,000	15,000,000
Minimum Net Worth Required for Compliance			20,000,000	20,000,000
Line of Credit Facility, Fair Value of Amount Outstanding			$ 0	$ 0
Outstanding Borrowing Limit Based on Eligible Receivables, Percentage			85.00%	85.00%
Covenant Ratio of Short Term Asset to Short Term Liabilities			110.00%	110.00%
Minimum Liquidity Amount			$ 10,000,000	$ 10,000,000
Letters of Credit Outstanding, Amount			$ 2,400,000	$ 2,400,000
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.25%
Not Comply with Liquidity Requirement [Member] | Prime Rate [Member] | Revolving Credit Facility [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				0.25%
[1]	As of June 29, 2018 and December 31, 2017, loans backed by French R&D tax credit receivables were $12.0 million and $17.7 million, respectively. As of June 29, 2018, the TVN French Subsidiary had an aggregate of $24.0 million of R&D tax credit receivables from the French government from 2018 through 2022. See Note 6, “Balance Sheet Components” for additional information. These tax loans have a fixed rate of 0.6%, plus EURIBOR 1 month + 1.3% and mature between 2018 through 2020. The remaining loans of $2.4 million at June 29, 2018, primarily relate to financial support from French government agencies for R&D innovation projects at minimal interest rates, and these loans mature between 2018 through 2025.

Convertible Notes, Other Debt63

Convertible Notes, Other Debts And Capital Leases - Convertible Note Roll Forward (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 29, 2018	Dec. 31, 2017	Dec. 31, 2015
Debt Instrument [Line Items]
Principal amount	$ 128,250	$ 128,250	$ 128,250
Less: Debt discount, net of amortization	(14,767)	(17,404)
Less: Debt issuance costs, net of amortization	(1,781)	(2,098)
Carrying amount	$ 111,702	$ 108,748
Remaining amortization period (years)	2 years 4 months 24 days	2 years 10 months 28 days
Effective interest rate on liability component	9.94%	9.94%
Carrying amount of equity component	$ 26,062	$ 26,062

Convertible Notes, Other Debt64

Convertible Notes, Other Debts And Capital Leases - Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Debt Disclosure [Abstract]
Contractual interest expense	$ 1,282	$ 1,282	$ 2,565	$ 2,565
Amortization of debt discount	1,340	1,214	2,637	2,388
Amortization of debt issuance costs	161	146	317	288
Total interest expense recognized	$ 2,783	$ 2,642	$ 5,519	$ 5,241

Convertible Notes , Other Debts

Convertible Notes , Other Debts And Capital Leases - Other Debt and Capital Lease Obligations (Details) - USD ($) $ in Thousands		Jun. 29, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Financing from French government agencies related to various government incentive programs (1)	[1]	$ 14,401	$ 20,565
Term loans		1,081	1,282
Obligations under capital leases		559	1,099
Total debt obligations		16,041	22,946
Less: current portion		(1,723)	(7,610)
Long-term portion		$ 14,318	$ 15,336
[1]	As of June 29, 2018 and December 31, 2017, loans backed by French R&D tax credit receivables were $12.0 million and $17.7 million, respectively. As of June 29, 2018, the TVN French Subsidiary had an aggregate of $24.0 million of R&D tax credit receivables from the French government from 2018 through 2022. See Note 6, “Balance Sheet Components” for additional information. These tax loans have a fixed rate of 0.6%, plus EURIBOR 1 month + 1.3% and mature between 2018 through 2020. The remaining loans of $2.4 million at June 29, 2018, primarily relate to financial support from French government agencies for R&D innovation projects at minimal interest rates, and these loans mature between 2018 through 2025.

Convertible Notes, Other Debt66

Convertible Notes, Other Debts And Capital Leases - Debt Maturities (Details) $ in Thousands	Jun. 29, 2018USD ($)
Debt Disclosure [Abstract]
Capital Leases, Future Minimum Payments, Remainder of Fiscal Year	$ 395
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	864
Capital Leases, Future Minimum Payments Due in Two Years	92
Long-term Debt, Maturities, Repayments of Principal in Year Two	6,879
Capital Leases, Future Minimum Payments Due in Three Years	49
Long-term Debt, Maturities, Repayments of Principal in Year Three	6,687
Capital Leases, Future Minimum Payments Due in Four Years	23
Long-term Debt, Maturities, Repayments of Principal in Year Four	497
Capital Leases, Future Minimum Payments Due in Five Years	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	457
Capital Leases, Future Minimum Payments Due Thereafter	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	98
Capital Leases, Future Minimum Payments Due	559
Long-term Debt	$ 15,482

Employee Benefit Plans and St67

Employee Benefit Plans and Stock-based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Dec. 31, 2017	Jan. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	$ 0	$ 0	$ 0	$ 0
Total stock-based compensation	3,012,000	$ 4,136,000	8,769,000	7,387,000
Defined Benefit Plan, Benefit Obligation	5,000,000		5,000,000		$ 5,000,000
Liability, Defined Benefit Pension Plan, Current	100,000		100,000
Liability, Defined Benefit Pension Plan, Noncurrent	4,900,000		$ 4,900,000
Discretionary contributions of plan			25.00%
Percent of employees' gross pay eligible for matching			4.00%
Maximum contribution amount per participant			$ 1,000
Contributions in period			214,000	$ 285,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 13,300,000		$ 13,300,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			1 year 9 months 18 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	1,800,000		1,800,000
Expected term (years)		4 years 3 months 18 days		4 years 3 months 18 days
Volatility		43.00%		43.00%
Risk-free interest rate		1.70%		1.70%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		0.00%		0.00%
Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			969,598
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			869,598
Total stock-based compensation	$ 100,000		$ 3,400,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 300,000		$ 300,000
Market-based awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	40,000				344,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			0
Total stock-based compensation	$ 100,000		$ 200,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	18 months				3 years
Aggregate Grant Date Fair Value of Market-Based Restricted Stock Units	$ 1,300,000		1,300,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 100,000		$ 100,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			1,300,000
Common Stock, Capital Shares Reserved for Future Issuance	5,300,000		5,300,000
Discount Percentage On Purchase Of Stock			15.00%
Percentage of fair market value of Common Stock to purchase shares			85.00%
Value Of Stock Purchase Right Percentage Of Put Option			15.00%
Equity Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in Period, Number of Shares			0
TVN [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payment for Pension and Other Postretirement Benefits			$ 0
Director Option Plans 2002 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			400,000
Accounting Standards Update 2016-09 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Modified Retrospective Cumulative Effect Adjustment to Retained Earnings						$ 69,000

Employee Benefit Plans and St68

Employee Benefit Plans and Stock-based Compensation - Summary of Stock Options Outstanding (Detail) - Stock Options Outstanding [Member] $ / shares in Units, shares in Thousands	6 Months Ended
	Jun. 29, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning balance | shares	3,880
Weighted Average Exercise Price, Beginning balance | $ / shares	$ 6.04
Grants in Period, Number of Shares | shares	0
Grants in Period, Weighted Average Exercise Price Per Share | $ / shares	$ 0
Number of Shares, Options exercised | shares	(87)
Weighted Average Exercise Price, Options exercised | $ / shares	$ 2.94
Number of Shares, Forfeited or cancelled | shares	(35)
Weighted Average Exercise Price, Forfeited or cancelled | $ / shares	$ 4.76
Canceled or expired | shares	(538)
Canceled or Expired, Weighted Average Exercise Price | $ / shares	$ 8.75
Number of Shares, Ending balance | shares	3,220
Weighted Average Exercise Price, Ending balance | $ / shares	$ 5.69
Weighted Average Remaining Contractual Term	2 years 9 months 18 days
Aggregate Intrinsic Value | $	$ 866,800
Number of Shares, Vested and expected to vest | shares	3,208
Weighted Average Exercise Price, Vested and expected to vest | $ / shares	$ 5.69
Weighted Average Remaining Contractual Term (Years), Vested and expected to vest	2 years 9 months 18 days
Aggregate Intrinsic Value, Vested and expected to vest | $	$ 859,300
Number of Shares, Exercisable | shares	2,958
Weighted Average Exercise Price, Exercisable | $ / shares	$ 5.77
Weighted Average Remaining Contractual Term (Years), Exercisable	2 years 8 months 12 days
Aggregate Intrinsic Value, Exercisable | $	$ 696,100

Employee Benefit Plans and St69

Employee Benefit Plans and Stock-based Compensation - Summary of Restricted Stock Units Outstanding (Detail) - Restricted Stock Units Outstanding [Member] shares in Thousands	6 Months Ended
	Jun. 29, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Units, Beginning balance | shares	2,904
Weighted Average Grant Date Fair Value, Beginning balance | $ / shares	$ 5.09
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares	3,293
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 3.74
Number of Units, Shares released | shares	(2,220)
Vested in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 4.75
Number of Units, Forfeited or cancelled | shares	(183)
Weighted Average Grant Date Fair Value, Forfeited or cancelled | $ / shares	$ 5.09
Number of Units, Ending balance | shares	3,794
Weighted Average Grant Date Fair Value, Ending balance | $ / shares	$ 4.12

Employee Benefit Plans and St70

Employee Benefit Plans and Stock-based Compensation - Summary of Projected Benefit Obligation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Employee Benefits and Share-based Compensation, Noncash [Abstract]
Service cost	$ 63	$ 55	$ 126	$ 110
Interest cost	19	16	38	32
Recognized net actuarial loss	0	2	0	3
Net periodic benefit cost included in operating loss	$ 82	$ 73	$ 164	$ 145

Employee Benefit Plans and St71

Employee Benefit Plans and Stock-based compensation - Stock-based Compensation in Opex (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 3,012	$ 4,136	$ 8,769	$ 7,387
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	448	700	963	1,145
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	818	1,337	2,622	2,314
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	1,746	2,099	5,184	3,928
Operating Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 2,564	$ 3,436	$ 7,806	$ 6,242

Employee Benefit Plans and St72

Employee Benefit Plans and Stock-based Compensation - Valuation Assumptions for Stock Options (Details) - Stock Options [Member]	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)	4 years 3 months 18 days	4 years 3 months 18 days
Volatility	43.00%	43.00%
Risk-free interest rate	1.70%	1.70%
Expected dividends	0.00%	0.00%

Employee Benefit Plans and St73

Employee Benefit Plans and Stock-based Compensation - Summary of Stock Awards Valuation Assumptions (Details) - Employee Stock Purchase Plan - $ / shares	6 Months Ended
	Jul. 02, 2018	Jul. 03, 2017
Purchase Period July 3, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)		6 months 1 day
Volatility		41.00%
Risk-free interest rate		1.00%
Expected dividends		0.00%
Estimated weighted average fair value per share at purchase date		$ 1.40
Scenario, Forecast [Member] | Purchase Period July 2, 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)	6 months 1 day
Volatility	60.00%
Risk-free interest rate	1.70%
Expected dividends	0.00%
Estimated weighted average fair value per share at purchase date	$ 1.34

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Loss before income taxes	$ (2,022)	$ (30,921)	$ (14,638)	$ (55,180)
Provision for income taxes	$ 891	$ 579	$ 1,969	$ 347
Effective income tax rate	(44.10%)	(1.90%)	(13.50%)	(0.60%)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2017	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Dec. 31, 2017	Mar. 31, 2017
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits		$ 17,900		$ 17,900
Effective income tax rate		(44.10%)	(1.90%)	(13.50%)	(0.60%)
Federal statutory income tax rate				21.00%
Unrecognized tax benefits that would impact the provision for income taxes		$ 1,100		$ 1,100
Interest and possible penalties related to uncertain tax positions		500		500
Decrease in Unrecognized Tax Benefits is Reasonably Possible		1,500		1,500
Accumulated deficit		$ (2,062,988)		$ (2,062,988)		$ (2,057,812)
Accounting Standards Update 2016-09 [Member]
Income Tax Contingency [Line Items]
Accumulated deficit	$ 0
Accounting Standards Update 2016-09 [Member] | Deferred Tax Assets Gross
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	4,600
Accounting Standards Update 2016-09 [Member] | Valuation Allowance of Deferred Tax Assets
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	4,600
Accounting Standards Update 2016-16 [Member]
Income Tax Contingency [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax	$ 1,400
Deferred Tax Assets, Net							$ 1,100
Deferred Tax Assets, Valuation Allowance							2,100
Deferred Tax Assets, Tax Deferred Expense							$ 300

Net Loss Per Share - Numerators

Net Loss Per Share - Numerators and Denominators of Basic and Diluted Net Income (Loss) Per Share Computations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Numerator:
Net loss	$ (2,913)	$ (31,500)	$ (16,607)	$ (55,527)
Denominator:
Basic and diluted	85,304	80,590	84,616	80,203
Net loss per share:
Basic and diluted	$ (0.03)	$ (0.39)	$ (0.20)	$ (0.69)

Net Loss Per Share - Anti-dilut

Net Loss Per Share - Anti-dilutive Securities (Detail) - $ / shares		3 Months Ended		6 Months Ended
		Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive equity awards outstanding	[1]	7,883,000	9,374,000	7,706,000	8,974,000
Potential Common Shares Upon Notes Conversion If Only Settled In Shares		22,304,348	22,304,348	22,304,348	22,304,348
Debt Instrument, Convertible, Conversion Price		$ 5.75	$ 5.75	$ 5.75	$ 5.75	$ 5.75
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive equity awards outstanding		3,234,000	4,614,000	3,469,000	4,753,000
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive equity awards outstanding		3,326,000	3,400,000	2,766,000	3,054,000
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive equity awards outstanding		541,000	578,000	689,000	385,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive equity awards outstanding	[2]	782,000	782,000	782,000	782,000
[1]	Excluded from the table above are the Notes, which are convertible under certain conditions into an aggregate of 22,304,348 shares of common stock. (See Note 9, “Convertible Notes, Other Debts and Capital Leases” for additional information on the Notes). Since the Company’s intent is to settle the principal amount of the Notes in cash, the treasury stock method is being used to calculate any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread will have a dilutive impact on diluted net income per share when the Company’s average market price of its common stock for a given period exceeds the conversion price of $5.75 per share.
[2]	On September 26, 2016, in connection with the execution of a product supply agreement pursuant to which an affiliate of Comcast Corporation (together with Comcast Corporation, “Comcast”) may, in its sole discretion, purchase from the Company licenses to certain of the Company’s software products, the Company granted Comcast a warrant to purchase shares of its common stock. (See Note 13, “Warrants” for additional information).

Warrants (Details)

Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017	Dec. 31, 2018	Sep. 26, 2016
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						7,816,162
Class of Warrant or Right, Exercise Price of Warrants or Rights						$ 4.76
Fair Value Adjustment of Warrants	$ 284		$ 395
Comcast Product Supply Agreement [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding						781,617
Fair Value Assumptions, Expected Dividend Rate			0.00%
Comcast Milestones Achievement [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Unissued						1,954,042
Comcast Exceeding Specified Cumulative Purchase Volume [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Unissued						1,172,425
Sales Revenue, Goods, Net [Member] | Comcast Product Supply Agreement [Member]
Class of Warrant or Right [Line Items]
Fair Value Adjustment of Warrants	300	$ 0	$ 400	$ 400
Prepaid Expenses and Other Current Assets [Member]
Class of Warrant or Right [Line Items]
Prepaid Warrants Incentive	$ 600		$ 600
Scenario, Forecast [Member] | Prepaid Expenses and Other Current Assets [Member]
Class of Warrant or Right [Line Items]
Prepaid Warrants Incentive					$ 1,000

Segment Information - Summary F

Segment Information - Summary Financial Infomation by reportable segments (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 29, 2018USD ($)		Jun. 30, 2017USD ($)	Jun. 29, 2018USD ($)segment	Jun. 30, 2017USD ($)
Segment Reporting Information [Line Items]
Revenue	$ 99,160		$ 82,315	$ 189,287	$ 165,258
Gross Profit	51,603		33,815	98,786	74,223
Operating Income (Loss)	642		(27,422)	$ (8,685)	(48,580)
Number of Reportable Segments | segment				2
Video [Member]
Segment Reporting Information [Line Items]
Revenue	79,208	[1]	73,379	$ 150,956	147,721
Gross Profit	43,558	[1]	37,720	84,784	78,493
Operating Income (Loss)	6,239	[1]	(8,947)	8,234	(14,783)
Cable Access [Member]
Segment Reporting Information [Line Items]
Revenue	20,236	[1]	8,936	38,726	17,537
Gross Profit	10,187	[1]	1,699	18,827	3,909
Operating Income (Loss)	540	[1]	(7,411)	(973)	(13,491)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	99,444	[1]	82,315	189,682	165,258
Gross Profit	53,745	[1]	39,419	103,611	82,402
Operating Income (Loss)	$ 6,779	[1]	(16,358)	$ 7,261	(28,274)
Operating Income (Loss) [Member]
Segment Reporting Information [Line Items]
Prior period reclassification adjustment			$ 2,100		$ 3,200
[1]	The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company has prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the three and six months ended June 30, 2017 compared to the Company’s historical approach was an increase in operating loss of $2.1 million and $3.2 million, respectively, from the Video segment and a corresponding decrease in operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments.

Segment Information Segment Inc

Segment Information Segment Income or Loss Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 29, 2018		Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ 642		$ (27,422)	$ (8,685)	$ (48,580)
Amortization of warrants	(284)			(395)
Unallocated Corporate Expenses	(50,961)		(61,237)	(107,471)	(122,803)
Stock-based compensation	(3,012)		(4,136)	(8,769)	(7,387)
Amortization of intangibles	(2,095)		(2,075)	(4,194)	(4,144)
Nonoperating Income (Expense)	(2,664)		(3,499)	(5,953)	(6,600)
Loss before income taxes	(2,022)		(30,921)	(14,638)	(55,180)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	6,779	[1]	(16,358)	7,261	(28,274)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Unallocated Corporate Expenses	$ (746)		$ (4,853)	$ (2,588)	$ (8,775)
[1]	The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company has prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the three and six months ended June 30, 2017 compared to the Company’s historical approach was an increase in operating loss of $2.1 million and $3.2 million, respectively, from the Video segment and a corresponding decrease in operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments.

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments Under Non-cancelable Operating Leases (Detail) $ in Thousands	Jun. 29, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2018 (remaining six months)	$ 6,505
2,019	11,420
2,020	8,379
2,021	2,907
2,022	2,431
Thereafter	10,758
Total	$ 42,400

Commitments and Contingencies82

Commitments and Contingencies - Summary of Warranty Accrual Included in Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period	$ 4,522	$ 4,585	$ 4,381	$ 4,862
Accrual for current period warranties	1,714	1,277	3,450	2,495
Warranty costs incurred	(1,589)	(1,720)	(3,184)	(3,215)
Balance at end of period	$ 4,647	$ 4,142	$ 4,647	$ 4,142

Commitments and Contingencies83

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Oct. 24, 2017USD ($)	Oct. 30, 2011Patents	Sep. 29, 2017USD ($)	Jun. 29, 2018USD ($)	Dec. 31, 2017USD ($)
Other Commitments [Line Items]
Non-cancelable purchase commitments				$ 38.7
Maximum amount of potential future payments under the company's financial guarantees				3.1
Contract Manufacturing [Member]
Other Commitments [Line Items]
Bank Guarantees and Standby Letters of Credit				0.8
Indemnification [Member]
Other Commitments [Line Items]
Accrual for indemnification provisions				0
TVN [Member] | Guarantee Obligations [Member]
Other Commitments [Line Items]
Bank Guarantees and Standby Letters of Credit				1.3
Avid [Member]
Other Commitments [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number | Patents		2
Estimated Litigation Liability			$ 6
Payments for litigation settlement	$ 2.5
Avid [Member] | Selling, General and Administrative Expenses [Member]
Other Commitments [Line Items]
Litigation Settlement, Expense			$ 6
Settled Litigation Payment Second Quarter of 2019 [Member] | Avid [Member]
Other Commitments [Line Items]
Estimated Litigation Liability, Noncurrent				1.5
Settled Litigation Payment Third Quarter of 2020 [Member] | Avid [Member]
Other Commitments [Line Items]
Estimated Litigation Liability, Noncurrent				2
Foreign Line of Credit [Member] | Performance Guarantee [Member] | Guarantee Obligations [Member]
Other Commitments [Line Items]
Line of Credit Facility, Current Borrowing Capacity					$ 2
Domestic Line of Credit [Member] | Performance Guarantee [Member] | Guarantee Obligations [Member]
Other Commitments [Line Items]
Bank Guarantees and Standby Letters of Credit					$ 2.2
Line of Credit Facility, Fair Value of Amount Outstanding				$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Comcast Milestone Acceptance Of Completion Of Field Trials [Member] - Subsequent Event [Member] $ in Millions	Jul. 31, 2018USD ($)shares
Subsequent Event [Line Items]
Warrant Shares Vested And Exercisable | shares	1,172,425
Fair Value of Warrants On Vesting Date Using Black-Scholes Option Model | $	$ 2.3