Infinera (INFN) 10-Q 1 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 24, 2016	Oct. 28, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 24, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	INFN
Entity Registrant Name	INFINERA CORP
Entity Central Index Key	1,138,639
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		144,573,314

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Current assets:
Cash and cash equivalents	$ 130,996	$ 149,101
Short-term investments	136,643	125,561
Short-term restricted cash	9,700	0
Accounts receivable, net of allowance for doubtful accounts of $807 in 2016 and $630 in 2015	152,467	186,243
Inventory	231,528	174,699
Prepaid expenses and other current assets	30,520	29,511
Total current assets	691,854	665,115
Property, plant and equipment, net	120,137	110,861
Intangible assets	133,939	156,319
Goodwill	187,927	191,560
Long-term investments	72,439	76,507
Cost-method investment	19,500	14,500
Long-term restricted cash	6,467	5,310
Other non-current assets	4,196	4,009
Total assets	1,236,459	1,224,181
Current liabilities:
Accounts payable	76,789	92,554
Accrued expenses	37,857	33,736
Accrued compensation and related benefits	37,942	49,887
Accrued warranty	15,875	17,889
Deferred revenue	38,063	42,977
Total current liabilities	206,526	237,043
Long-term debt, net	130,924	123,327
Accrued warranty, non-current	22,746	20,955
Deferred revenue, non-current	18,369	13,881
Deferred tax liability	31,419	35,731
Other long-term liabilities	18,161	16,183
Commitments and contingencies (Note 16)
Stockholders’ equity:
Preferred stock, $0.001 par value Authorized shares – 25,000 and no shares issued and outstanding	0	0
Issued and outstanding shares – 144,536 as of September 24, 2016 and 140,197 as of December 26, 2015	145	140
Additional paid-in capital	1,341,501	1,300,301
Accumulated other comprehensive income (loss)	(6,010)	1,123
Accumulated deficit	(527,322)	(539,413)
Total Infinera Corporation stockholders’ equity	808,314	762,151
Noncontrolling interest	0	14,910
Total stockholders' equity	808,314	777,061
Total liabilities and stockholders’ equity	$ 1,236,459	$ 1,224,181

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Statement of Financial Position [Abstract]
Net of allowance for doubtful accounts	$ 807	$ 630
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, authorized shares (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	144,536,000	140,197,000
Common stock, shares outstanding (in shares)	144,536,000	140,197,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Revenue:
Product	$ 156,188	$ 202,365	$ 599,802	$ 542,190
Services	29,264	30,107	89,290	84,490
Total revenue	185,452	232,472	689,092	626,680
Cost of revenue:
Cost of product	91,064	117,154	331,564	306,151
Cost of services	9,786	12,513	32,842	32,816
Total cost of revenue	100,850	129,667	364,406	338,967
Gross profit	84,602	102,805	324,686	287,713
Operating expenses:
Research and development	50,855	45,466	164,541	128,144
Sales and marketing	27,960	24,721	88,434	67,298
General and administrative	16,646	18,358	51,617	46,324
Total operating expenses	95,461	88,545	304,592	241,766
Income (loss) from operations	(10,859)	14,260	20,094	45,947
Other income (expense), net:
Interest income	647	406	1,764	1,371
Interest expense	(3,313)	(3,014)	(9,644)	(8,851)
Other gain (loss), net	(188)	(3,293)	(1,116)	1,788
Total other income (expense), net	(2,854)	(5,901)	(8,996)	(5,692)
Income (loss) before income taxes	(13,713)	8,359	11,098	40,255
Provision for (benefit from) income taxes	(2,416)	(151)	(725)	1,473
Net income (loss)	(11,297)	8,510	11,823	38,782
Less: Loss attributable to noncontrolling interest	(125)	0	(503)	0
Net income (loss) attributable to Infinera Corporation	$ (11,172)	$ 8,510	$ 12,326	$ 38,782
Net income (loss) per common share attributable to Infinera Corporation:
Basic (in usd per share)	$ (0.08)	$ 0.06	$ 0.09	$ 0.30
Diluted (in usd per share)	$ (0.08)	$ 0.06	$ 0.08	$ 0.27
Weighted average shares used in computing net income (loss) per common share:
Basic (in shares)	143,850	134,834	142,350	131,007
Diluted (in shares)	143,850	145,300	145,921	141,082

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (11,297)	$ 8,510	$ 11,823	$ 38,782
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale investments	(166)	90	476	279
Foreign currency translation adjustment	(4,107)	4,729	(7,609)	4,699
Net change in accumulated other comprehensive income (loss)	(4,273)	4,819	(7,133)	4,978
Less: Comprehensive loss attributable to noncontrolling interest	(125)	0	(503)	0
Comprehensive income (loss) attributable to Infinera Corporation	$ (15,445)	$ 13,329	$ 5,193	$ 43,760

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015
Statement of Cash Flows [Abstract]
Net income	$ 11,823	$ 38,782
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	45,764	22,094
Amortization of debt discount and issuance costs	7,598	6,873
Amortization of premium on investments	925	2,405
Stock-based compensation expense	29,191	23,868
Other loss (gain)	261	(448)
Changes in assets and liabilities:
Accounts receivable	33,044	28,838
Inventory	(61,078)	(8,901)
Prepaid expenses and other assets	(1,625)	(6,058)
Accounts payable	(13,935)	(2,339)
Accrued liabilities and other expenses	(7,580)	(7,196)
Deferred revenue	(805)	700
Accrued warranty	(179)	8,742
Net cash provided by operating activities	43,404	107,360
Cash Flows from Investing Activities:
Purchase of available-for-sale investments	(118,017)	(126,940)
Proceeds from sales of available-for-sale investments	0	67,303
Proceeds from maturities and calls of investments	110,554	178,717
Acquisition of business, net of cash acquired	0	(144,445)
Realized gain from forward contract for business acquisition	0	1,053
Purchase of cost-method investment	(5,000)	0
Purchase of property and equipment	(32,878)	(26,710)
Change in restricted cash	(4,950)	127
Net cash used in investing activities	(50,291)	(50,895)
Cash Flows from Financing Activities:
Security pledge related to Squeeze-out Proceedings	(5,921)	0
Acquisition of noncontrolling interest	(16,771)	0
Proceeds from issuance of common stock	16,486	23,433
Minimum tax withholding paid on behalf of employees for net share settlement	(3,592)	(5,043)
Net cash provided by (used in) financing activities	(9,798)	18,390
Effect of exchange rate changes on cash	(1,420)	(247)
Net change in cash and cash equivalents	(18,105)	74,608
Cash and cash equivalents at beginning of period	149,101	86,495
Cash and cash equivalents at end of period	130,996	161,103
Supplemental disclosures of cash flow information:
Cash paid for income taxes, net of refunds	5,557	2,552
Cash paid for interest	1,445	1,317
Supplemental schedule of non-cash investing activities:
Transfer of inventory to fixed assets	5,211	5,861
Common stock issued in connection with acquisition	$ 0	$ 169,507

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 24, 2016
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation Infinera Corporation (the "Company") prepared its interim condensed consolidated financial statements that accompany these notes in conformity with U.S. generally accepted accounting principles ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the "SEC"), consistent in all material respects with those applied in the Company’s Annual Report on Form 10-K for the fiscal year ended December 26, 2015. The Company has made certain estimates, assumptions and judgments that can affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the condensed consolidated financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Significant estimates, assumptions and judgments made by management include revenue recognition, stock-based compensation, inventory valuation, accrued warranty, business combinations, fair value measurement of investments and accounting for income taxes. Other estimates, assumptions and judgments made by management include allowances for sales returns, allowances for doubtful accounts, useful life of intangible assets, property, plant and equipment, and fair value measurement of the liability component of the Company's $150.0 million of 1.75% convertible senior notes due June 1, 2018 (the "Notes"). Management believes that the estimates and judgments upon which they rely are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent there are material differences between these estimates and actual results, the Company’s condensed consolidated financial statements will be affected. The interim financial information is unaudited, but reflects all adjustments that are, in management’s opinion, necessary to provide a fair presentation of results for the interim periods presented. All adjustments are of a normal recurring nature. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company reclassified certain amounts reported in previous periods to conform to the current presentation. This interim information should be read in conjunction with the consolidated financial statements in the Company’s Annual Report on Form 10-K for the fiscal year ended December 26, 2015. For the three and nine months ended September 24, 2016, cost of revenue was lower by $2.0 million related to a change in estimate associated with the treatment of manufacturing variances as the Company transitioned the former Transmode business onto the Company’s enterprise resource planning ("ERP") system. To date, a few of the Company’s customers have accounted for a significant portion of its revenue. For the three months ended September 24, 2016 , two customers individually accounted for 16% and 12% of the Company's total revenue, respectively, and for the corresponding period in 2015, two customers individually accounted for 26% and 16% of the Company's total revenue, respectively. For the nine months ended September 24, 2016 , two customers individually accounted for 16% and 10% of the Company's total revenue, respectively, and for the corresponding period in 2015, two customers individually accounted for 18% and 15% of the Company's total revenue, respectively. There have been no material changes in the Company’s significant accounting policies for the nine months ended September 24, 2016 as compare d to those disclosed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 26, 2015, with the exception of the Company's adoption of Accounting Standards Update 2016-09, "Improvements to Employee Share-Based Payment Accounting") ("ASU 2016-09"). For more information, see Note 2, "Recent Accounting Pronouncements" to the Notes to Condensed Consolidated Financial Statements.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 24, 2016
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update 2016-15, "Statement of Cash Flows (Topic 320): Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15"), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain transactions are presented and classified in the statement of cash flows. This guidance is effective for the Company in its first quarter of fiscal 2018 and will be applied on a retrospective basis. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its condensed consolidated financial statements. In June 2016, the FASB issued Accounting Standards Update 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"), which requires measurement and recognition of expected credit losses for financial assets held. This guidance is effective for the Company in its first quarter of fiscal 2020 and early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-13 will have on its condensed consolidated financial statements. In May 2016, the FASB issued Accounting Standards Update 2016-11, "Revenue Recognition (Topic 605) and Derivatives and Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting (SEC Update)" ("ASU 2016-11"), which rescinds various standards codified as part of Topic 605, Revenue Recognition in relation to the future adoption of Topic 606. These rescissions include changes to topics pertaining to revenue and expense recognition for freight services in process, accounting for shipping and handling fees and costs, and accounting for consideration given by a vendor to a customer. This guidance is effective for the Company in its first quarter of fiscal 2018 and early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-11 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, which includes provisions intended to simplify various aspects related to how share-based payments are accounted for and presented in the financial statements, including the income tax effects of share-based payments and accounting for forfeitures. ASU 2016-09 requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows, and allows for an accounting policy election to either estimate the number of forfeitures (current U.S. GAAP) or account for forfeitures when they occur, amongst other provisions. This standard provides for prospective, retrospective, or modified retrospective adoption of each of the changes. ASU 2016-09 is effective for the Company in its first quarter of fiscal 2017 and early adoption is permitted. The Company elected to early adopt ASU 2016-09 as of its third fiscal quarter beginning on June 26, 2016. The Company also elected to change its accounting policy to account for forfeitures when they occur on a modified retrospective basis. The adoption of ASU 2016-09 and the change in the Company’s accounting policy resulted in a $0.2 million increase to additional paid-in capital and accumulated deficit as of December 26, 2015. The Company also recorded $0.3 million of stock-based compensation expense during the three months ended September 24, 2016 to true-up for the differential between the amount of stock-based compensation cost previously recorded for the first six months ended June 25, 2016 and the amount that would have been recorded without assuming forfeitures. Additionally, the Company adopted the change in presentation in the condensed consolidated statement of cash flows related to excess tax benefits on a prospective basis. Accordingly, prior periods have not been adjusted. There was no impact for the change in presentation in the condensed consolidated statement of cash flows related to statutory tax withholding requirements as the Company has historically classified the statutory tax withholding as a financing activity in its consolidated statement of cash flows. In February 2016, the FASB issued Accounting Standards Update 2016-02, "Leases (Topic 842)" ("ASU 2016-02"), which amends the existing accounting standards for leases. The new standard requires lessees to record a right-of-use asset and a corresponding lease liability on the balance sheet (with the exception of short-term leases). For lessees, leases will continue to be classified as either operating or financing in the income statement. This guidance is effective for the Company in its first quarter of fiscal 2019 and early adoption is permitted. ASU 2016-02 is required to be applied with a modified retrospective approach and requires application of the new standard at the beginning of the earliest comparative period presented. The Company is currently evaluating the impact the adoption of ASU 2016-02 will have on its consolidated financial statements. In September 2015, the FASB issued Accounting Standards Update 2015-16, "Business Combinations and Simplifying the Accounting for Measurement-Period Adjustments" ("ASU 2015-16"), which eliminates the requirement for an acquirer in a business combination to account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The Company adopted ASU 2015-16 during the first quarter of fiscal 2016. The Company's adoption of ASU 2015-16 had no impact on the Company's financial position, results of operations or cash flow. In July 2015, the FASB issued Accounting Standards Update 2015-11, "Simplifying the Measurement of Inventory" ("ASU 2015-11"), to simplify the guidance on the subsequent measurement of inventory, excluding inventory measured using last-in, first-out or the retail inventory method. Under ASU 2015-11, inventory should be at the lower of cost and net realizable value. This guidance is effective for the Company in its first quarter of fiscal 2017 and early adoption permitted. The Company is currently evaluating the impact the adoption of ASU 2015-11 will have on its consolidated financial statements. In April 2015, the FASB issued Accounting Standards Update 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03"), which changes the presentation of debt issuance costs in financial statements. ASU 2015-03 requires an entity to present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs will continue to be reported as interest expense. The Company adopted ASU 2015-03 during the first quarter of fiscal 2016. The December 26, 2015 balance sheet was retrospectively adjusted to reclassify $2.1 million from other non-current assets to a reduction of the Notes payable liability. In May 2014, the FASB issued Accounting Standards Update 2014-09, "Revenue from Contracts from Customers" ("ASU 2014-09"), which creates a single, joint revenue standard that is consistent across all industries and markets for companies that prepare their financial statements in accordance with GAAP. Under ASU 2014-09, an entity is required to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services. In July 2015, the FASB decided to delay the effective date of the new revenue standard by one year. In April 2016, the FASB issued Accounting Standards Update 2016-10, "Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing," which clarifies the implementation guidance on identifying performance obligations and licensing. In May 2016, the FASB issued Accounting Standards Update 2016-12, "Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients," which amends the guidance on collectability, noncash consideration, presentation of sales tax and transition. These standards will be effective for the Company's first quarter of 2018. The Company is currently evaluating the impact of these new standards on its consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 24, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Pursuant to the accounting guidance for fair value measurements and its subsequent updates, fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and it considers assumptions that market participants would use when pricing the asset or liability. Valuation techniques used by the Company are based upon observable and unobservable inputs. Observable or market inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s assumptions about market participant assumptions based on the best information available. Observable inputs are the preferred source of values. These two types of inputs create the following fair value hierarchy: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Prices or valuations that require management inputs that are both significant to the fair value measurement and unobservable. The Company measures its cash equivalents, foreign currency exchange forward contracts and marketable debt securities at fair value and classifies its investments in accordance with the fair value hierarchy. The Company’s money market funds and U.S. treasuries are classified within Level 1 of the fair value hierarchy and are valued based on quoted prices in active markets for identical securities. The Company classifies its certificates of deposit, commercial paper, U.S. agency notes, corporate bonds and foreign currency exchange forward contracts within Level 2 of the fair value hierarchy as follows: Certificates of Deposit The Company reviews market pricing and other observable market inputs for the same or similar securities obtained from a number of industry standard data providers. In the event that a transaction is observed for the same or similar security in the marketplace, the price on that transaction reflects the market price and fair value on that day. In the absence of any observable market transactions for a particular security, the fair market value at period end would be equal to the par value. These inputs represent quoted prices for similar assets or these inputs have been derived from observable market data. Commercial Paper The Company reviews market pricing and other observable market inputs for the same or similar securities obtained from a number of industry standard data providers. In the event that a transaction is observed for the same or similar security in the marketplace, the price on that transaction reflects the market price and fair value on that day and then follows a revised accretion schedule to determine the fair market value at period end. In the absence of any observable market transactions for a particular security, the fair market value at period end is derived by accreting from the last observable market price. These inputs represent quoted prices for similar assets or these inputs have been derived from observable market data accreted mathematically to par. U.S. Agency Notes The Company reviews trading activity and pricing for its U.S. agency notes as of the measurement date. When sufficient quoted pricing for identical securities is not available, the Company uses market pricing and other observable market inputs for similar securities obtained from a number of industry standard data providers. These inputs represent quoted prices for similar assets in active markets or these inputs have been derived from observable market data. Corporate Bonds The Company reviews trading activity and pricing for each of the corporate bond securities in its portfolio as of the measurement date and determines if pricing data of sufficient frequency and volume in an active market exists in order to support Level 1 classification of these securities. If sufficient quoted pricing for identical securities is not available, the Company obtains market pricing and other observable market inputs for similar securities from a number of industry standard data providers. In instances where multiple prices exist for similar securities, these prices are used as inputs into a distribution-curve to determine the fair market value at period end. Foreign Currency Exchange Forward Contracts As discussed in Note 5, "Derivative Instruments" to the Notes to Condensed Consolidated Financial Statements, the Company mainly holds non-speculative foreign exchange forward contracts to hedge certain foreign currency exchange exposures. The Company estimates the fair values of derivatives based on quoted market prices or pricing models using current market rates. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including interest rate curves, credit risk, foreign exchange rates, and forward and spot prices for currencies. The following tables represent the Company’s fair value hierarchy for its assets and liabilities measured at fair value on a recurring basis (in thousands): As of September 24, 2016 As of December 26, 2015 Fair Value Measured Using Fair Value Measured Using Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Money market funds $ 35,629 $ — $ — $ 35,629 $ 37,829 $ — $ — $ 37,829 Certificates of deposit — 2,602 — 2,602 — 5,001 — 5,001 Commercial paper — 40,325 — 40,325 — 10,997 — 10,997 Corporate bonds — 105,160 — 105,160 — 163,400 — 163,400 U.S. agency notes — 9,782 — 9,782 — 10,717 — 10,717 U.S. treasuries 56,209 — — 56,209 24,851 — — 24,851 Foreign currency exchange forward contracts — 208 — 208 — 490 — 490 Total assets $ 91,838 $ 158,077 $ — $ 249,915 $ 62,680 $ 190,605 $ — $ 253,285 Liabilities Foreign currency exchange forward contracts $ — $ (263 ) $ — $ (263 ) $ — $ (44 ) $ — $ (44 ) During the three and nine months ended September 24, 2016 , there were no transfers of assets or liabilities between Level 1 and Level 2 of the fair value hierarchy. Investments at fair value were as follows (in thousands): September 24, 2016 Adjusted Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Money market funds $ 35,629 $ — $ — $ 35,629 Certificates of deposit 2,600 2 — 2,602 Commercial paper 40,340 — (15 ) 40,325 Corporate bonds 105,215 21 (76 ) 105,160 U.S. agency notes 9,787 — (5 ) 9,782 U.S. treasuries 56,168 47 (6 ) 56,209 Total available-for-sale investments $ 249,739 $ 70 $ (102 ) $ 249,707 December 26, 2015 Adjusted Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Money market funds $ 37,829 $ — $ — $ 37,829 Certificates of deposit 5,000 1 — 5,001 Commercial paper 10,997 — — 10,997 Corporate bonds 163,797 — (397 ) 163,400 U.S. agency notes 10,786 — (69 ) 10,717 U.S. treasuries 24,894 — (43 ) 24,851 Total available-for-sale investments $ 253,303 $ 1 $ (509 ) $ 252,795 As of September 24, 2016 , the Company’s available-for-sale investments have a contractual maturity term of up to 24 months . Gross realized gains and losses on short-term and long-term investments for the three and nine months ended September 24, 2016 and September 26, 2015 were insignificant in all periods. The specific identification method is used to account for gains and losses on available-for-sale investments. As of September 24, 2016 and December 26, 2015, the Company held $90.4 million and $98.4 million of cash in banks, respectively, excluding restricted cash.

Cost-method Investments

Cost-method Investments	9 Months Ended
	Sep. 24, 2016
Investments, All Other Investments [Abstract]
Cost-method Investments	Cost-method Investments On September 20, 2016, the Company invested $5.0 million in a privately-held company. In addition to the $5.0 million investment, the transaction included a customer supply agreement and warrants to purchase $10 million of additional preferred stock. The warrants vest and become exercisable upon certain conditions being met. As of September 24, 2016 , the Company had investments totaling $19.5 million in two privately-held companies. These investments are accounted for as cost-method investments as the Company owns less than 20% of the voting securities and does not have the ability to exercise significant influence over operating and financial policies of either entity. The investments are carried at historical cost in the Company's condensed consolidated financial statements. The Company regularly evaluates the carrying value of these cost-method investments for impairment. If the Company believes that the carrying value of the cost basis investments is in excess of estimated fair value, the Company’s policy is to record an impairment charge in other income (expense), net, in the accompanying condensed consolidated statements of operations to adjust the carrying value to estimated fair value, when the impairment is deemed other-than-temporary. As of September 24, 2016 , no event had occurred that would adversely affect the carrying value of these investments and thus no impairment charges have been recorded for these cost-method investments.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 24, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Foreign Currency Exchange Forward Contracts The Company transacts business in various foreign currencies and has international sales, cost of sales, and expenses denominated in foreign currencies, and carries foreign-currency-denominated monetary assets and liabilities, subjecting the Company to foreign currency risk. The Company’s primary foreign currency risk management objective is to protect the U.S. dollar value of future cash flows and minimize the volatility of reported earnings. The Company utilizes foreign currency forward contracts, primarily short term in nature. Historically, the Company enters into foreign currency exchange forward contracts to manage its exposure to fluctuation in foreign exchange rates that arise from its euro and British pound denominated receivables and restricted cash balances. Gains and losses on these contracts are intended to offset the impact of foreign exchange rate fluctuations on the underlying foreign currency denominated accounts receivables and restricted cash, and therefore, do not subject the Company to material balance sheet risk. During 2016, the Company also entered into foreign currency exchange contracts to reduce the volatility of cash flows primarily related to forecasted revenues and expenses denominated in euro, British pound and Swedish kronor ("SEK"). The contracts are settled for U.S. dollars and SEK at maturity and at rates agreed to at inception of the contracts. The gains and losses on these foreign currency derivatives are recorded to the condensed consolidated statement of operations line item, in the current period, to which the item that is being economically hedged is recorded. For the three months ended September 24, 2016 and September 26, 2015, the before-tax effect of the foreign currency exchange forward contracts were a loss of $0.2 million and a gain of $0.3 million , respectively, and for the nine months ended September 24, 2016 and September 26, 2015, the before-tax effect of the foreign currency exchange forward contracts were a loss of $0.8 million and a loss of $3.1 million , respectively. In each of these periods, the impact of the gross gains and losses were offset by foreign exchange rate fluctuations on the underlying foreign currency denominated amounts. As of September 24, 2016 , the Company did not designate foreign currency exchange forward contracts as hedges for accounting purposes and accordingly, changes in the fair value are recorded in the accompanying condensed consolidated statements of operations. These contracts were with two high-quality institutions and the Company consistently monitors the creditworthiness of the counterparties. The fair value of derivative instruments in the Company’s condensed consolidated balance sheets was as follows (in thousands): As of September 24, 2016 As of December 26, 2015 Gross Notional (1) Prepaid Expense and Other Assets Other Accrued Liabilities Gross Notional (1) Prepaid Expense and Other Assets Other Accrued Liabilities Foreign currency exchange forward contracts Related to euro denominated receivables $ 24,207 $ — $ (262 ) $ 46,753 $ 319 $ (44 ) Related to British pound denominated receivables $ 3,749 208 — $ 6,686 171 — Related to restricted cash $ 258 — (1 ) $ 252 — — $ 208 $ (263 ) $ 490 $ (44 ) (1) Represents the face amounts of forward contracts that were outstanding as of the period noted.

Business Combination

Business Combination	9 Months Ended
	Sep. 24, 2016
Business Combinations [Abstract]
Business Combination	Business Combination On August 20, 2015 (the "Acquisition Date”), the Company completed its public offer to the shareholders of Transmode AB ("Transmode"), acquiring 95.8% of the outstanding common shares and voting interest in Transmode. Transmode is a metro packet-optical networking company based in Stockholm, Sweden. The combination of the two companies brings together a complementary set of customers, products, and technologies into one company. With the acquisition of Transmode, the Company now offers an end-to-end product portfolio of packet-optical solutions for metro, data center interconnect, long-haul and subsea networks. Shortly after the Acquisition Date, the Company initiated compulsory acquisition proceedings in accordance with Swedish law (the "Squeeze-out Proceedings") in order to acquire the remaining 4.2% , or 1.2 million Transmode shares, not tendered through the end of the offer period. As of the Acquisition Date, the fair value of the noncontrolling interest was approximately $15.4 million , which was based on the implied enterprise value of Transmode at the Acquisition Date. In August 2016, the Company received advance title and paid an undisputed purchase price of $16.8 million to acquire the remaining 4.2% of Transmode shares not tendered in the initial offer. The additional $16.8 million paid resulted in the elimination of the noncontrolling interest and an increase in additional paid-in capital. As of September 24, 2016, the Company continues to maintain a security pledge of approximately $5.9 million required by Swedish law until a final adjustment, if any, is determined. The final amount and timing of the final disposition are currently uncertain and will be determined by an arbitration tribunal at the completion of the Squeeze-out Proceedings. The Company has accounted for this transaction as a business combination in exchange for total consideration of $350.6 million , which consisted of the following (in thousands, except shares): Cash $ 181,133 Common stock (7.9 million shares) 169,507 Total $ 350,640 The fair value of the 7.9 million shares of common stock issued was determined based on the closing market price of the Company’s common stock on the Acquisition Date. The Company allocated the fair value of the purchase price of the acquisition to the tangible and intangible assets acquired as well as liabilities assumed, based on their estimated fair values. The excess of the purchase price over the fair values of these identifiable assets and liabilities was recorded as goodwill. The Company prepared an initial determination of the fair value of assets acquired and liabilities assumed as of the acquisition date using preliminary information. In accordance with Accounting Standard Codification 805, "Business Combinations," during the measurement period an acquirer shall retrospectively adjust the provisional amounts recognized at the acquisition date to reflect information obtained about facts and circumstances that existed as of the Acquisition Date that, if known, would have affected the measurement of the amounts recognized as of the Acquisition Date. Accordingly, the Company has recognized measurement period adjustments made during the first quarter of 2016 to the fair value of certain assets acquired and liabilities assumed as a result of additional information obtained. These adjustments were retrospectively applied to the Acquisition Date balance sheet. None of the adjustments had an impact on the Company’s previously reported results of operations. The following table summarizes the Company’s allocation of the purchase consideration based on the fair value of assets acquired and liabilities assumed as of the Acquisition Date (in thousands): Amounts Recognized as of Acquisition Date Measurement Period Adjustments Total Cash $ 36,688 $ — $ 36,688 Accounts receivable 16,183 — 16,183 Inventory 19,886 — 19,886 Other assets 8,320 — 8,320 Intangible assets, net 161,845 — 161,845 Goodwill 187,220 669 187,889 Current liabilities (24,320 ) (800 ) (25,120 ) Deferred tax liabilities (39,221 ) 131 (39,090 ) Long-term liabilities (589 ) — (589 ) Noncontrolling interest (15,372 ) — (15,372 ) Total net assets $ 350,640 $ — $ 350,640 The following table presents details of the identified intangible assets acquired at the Acquisition Date (in thousands): Fair Value Estimated Useful Life (Years) Trade name $ 234 0.5 Customer relationships 49,033 8 Developed technology 92,450 5 In-process technology 20,128 N/A Total $ 161,845 Goodwill generated from this business combination is primarily attributable to the synergies from combining the operations of Transmode with that of the Company, which resulted in expanded selling opportunities of both metro and long-haul solutions. The goodwill recognized is not tax deductible for Swedish income tax purposes. Noncontrolling interest was as follows (in thousands): September 24, 2016 December 26, 2015 Beginning noncontrolling interest $ 14,910 $ — Noncontrolling interest investment — 15,373 Acquisition of noncontrolling interest (14,407 ) — Loss attributable to noncontrolling interest (503 ) (463 ) Ending noncontrolling interest $ — $ 14,910

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 24, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill Goodwill is recorded when the purchase price of an acquisition exceeds the fair value of the net tangible and identified intangible assets acquired. The following table presents details of the Company’s goodwill during the nine months ended September 24, 2016 (in thousands): Balance as of December 26, 2015 $ 191,560 Foreign currency translation adjustments (3,633 ) Accumulated impairment loss — Balance as of September 24, 2016 $ 187,927 The gross carrying amount of goodwill may change due to the effects of foreign currency fluctuations as these assets are denominated in SEK. Intangible Assets The following tables present details of the Company’s intangible assets as of September 24, 2016 and December 26, 2015 (in thousands): September 24, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Useful Life (In Years) Intangible assets with finite lives: Trade names $ 234 $ (234 ) $ — — Customer relationships 49,042 (6,753 ) 42,289 6.9 Developed technology 100,285 (21,213 ) 79,072 4.0 Other intangible assets 819 (554 ) 265 4.9 Total intangible assets with finite lives $ 150,380 $ (28,754 ) $ 121,626 5.0 In-process technology 12,313 — 12,313 Total intangible assets $ 162,693 $ (28,754 ) $ 133,939 December 26, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Useful Life (In Years) Intangible assets with finite lives: Trade names $ 239 $ (168 ) $ 71 0.2 Customer relationships 49,991 (2,197 ) 47,794 7.7 Developed technology 94,256 (6,629 ) 87,627 4.6 Other intangible assets 819 (513 ) 306 5.6 Total intangible assets with finite lives $ 145,305 $ (9,507 ) $ 135,798 5.7 In-process technology 20,521 — 20,521 Total intangible assets $ 165,826 $ (9,507 ) $ 156,319 The gross carrying amount of intangible assets and the related amortization expense of intangible assets may change due to the effects of foreign currency fluctuations as these assets are denominated in SEK. Amortization expense was $6.7 million and $19.8 million for the three and nine months ended September 24, 2016 , respectively, and was $2.6 million for the three and nine months ended September 26, 2015. Intangible assets are carried at cost less accumulated amortization. Amortization expenses are recorded to the appropriate cost and expense categories. During the nine months ended September 24, 2016 , the Company transferred $7.8 million of its in-process technology to developed technology, which is being amortized over a maximum useful life of 7 years. In-process technology of $12.3 million as of September 24, 2016 is not subject to amortization. As such, the Company excluded it in the future amortization expense table below. The following table summarizes the Company’s estimated future amortization expense of intangible assets with finite lives as of September 24, 2016 (in thousands): Fiscal Years Total Remainder of 2016 2017 2018 2019 2020 2021 and Thereafter Total future amortization expense $ 121,626 $ 6,612 $ 26,487 $ 26,487 $ 25,879 $ 18,886 $ 17,275

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Sep. 24, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details	Balance Sheet Details The following table provides details of selected balance sheet items (in thousands): September 24, 2016 December 26, 2015 Inventory: Raw materials $ 37,199 $ 27,879 Work in process 65,540 52,599 Finished goods 128,789 94,221 Total inventory $ 231,528 $ 174,699 Property, plant and equipment, net: Computer hardware $ 12,741 $ 11,097 Computer software (1) 26,718 22,548 Laboratory and manufacturing equipment 215,690 189,168 Furniture and fixtures 2,060 1,897 Leasehold improvements 43,048 38,946 Construction in progress 27,976 31,060 Subtotal $ 328,233 $ 294,716 Less accumulated depreciation and amortization (208,096 ) (183,855 ) Total property, plant and equipment, net $ 120,137 $ 110,861 Accrued expenses: Loss contingency related to non-cancelable purchase commitments $ 6,293 $ 6,821 Professional and other consulting fees 4,198 5,363 Taxes payable 4,532 3,295 Royalties 5,376 4,290 Other accrued expenses 17,458 13,967 Total accrued expenses $ 37,857 $ 33,736 (1) Included in computer software at September 24, 2016 and December 26, 2015 were $9.1 million and $7.9 million , respectively, related to an ERP system that the Company implemented. The unamortized ERP costs at September 24, 2016 and December 26, 2015 were $4.3 million and $4.0 million , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 24, 2016
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) includes certain changes in equity that are excluded from net income. The following table sets forth the changes in accumulated other comprehensive income (loss) by component for the nine months ended September 24, 2016 (in thousands): Unrealized Gain (Loss) on Other Available-for-Sale Securities Foreign Currency Translation Accumulated Tax Effect Total Balance at December 26, 2015 $ (506 ) $ 2,389 $ (760 ) $ 1,123 Net current-period other comprehensive income (loss) 476 (7,609 ) — (7,133 ) Balance at September 24, 2016 $ (30 ) $ (5,220 ) $ (760 ) $ (6,010 )

Basic and Diluted Net Income (L

Basic and Diluted Net Income (Loss) Per Common Share	9 Months Ended
	Sep. 24, 2016
Earnings Per Share [Abstract]
Basic and Diluted Net Income (Loss) Per Common Share	Basic and Diluted Net Income (Loss) Per Common Share Basic net income (loss) per common share is computed by dividing net income (loss) attributable to Infinera Corporation by the weighted average number of common shares outstanding during the period. Diluted net income (loss) attributable to Infinera Corporation per common share is computed using net income (loss) attributable to Infinera Corporation and the weighted average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Potentially dilutive common shares include the assumed exercise of outstanding stock options, assumed release of outstanding restricted stock units ("RSUs") and performance stock units ("PSUs"), and assumed issuance of common stock under the Company’s 2007 Employee Stock Purchase Plan ("ESPP") using the treasury stock method. Potentially dilutive common shares also include the assumed conversion of convertible senior notes from the conversion spread (as discussed in Note 11, "Convertible Senior Notes"). The Company includes the common shares underlying PSUs in the calculation of diluted net income per share only when they become contingently issuable. In net loss periods, these potentially diluted common shares have been excluded from the diluted net loss calculation. The following table sets forth the computation of net income (loss) per common share – basic and diluted (in thousands, except per share amounts): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Numerator: Net income (loss) attributable to Infinera Corporation $ (11,172 ) $ 8,510 $ 12,326 $ 38,782 Denominator: Basic weighted average common shares outstanding 143,850 134,834 142,350 131,007 Effect of dilutive securities: Employee equity plans — 5,397 2,580 5,911 Assumed conversion of convertible senior notes from conversion spread — 5,069 991 4,164 Diluted weighted average common shares outstanding 143,850 145,300 145,921 141,082 Net income (loss) per common share attributable to Infinera Corporation Basic $ (0.08 ) $ 0.06 $ 0.09 $ 0.30 Diluted $ (0.08 ) $ 0.06 $ 0.08 $ 0.27 The Company incurred a net loss during the three months ended September 24, 2016, and as a result, potential common shares from options, RSUs, PSUs and assumed release of outstanding stock under the ESPP were not included in the diluted shares used to calculate net loss per share, as their inclusion would have been anti-dilutive. During the nine months ended September 24, 2016 and the three and nine months ended September 26, 2015, the effects of certain potentially outstanding shares were not included in the calculation of diluted net income per share as their effect were anti-dilutive under the treasury stock method or the performance condition of the award had not been met. During the nine months ended September 24, 2016 and the three and nine months ended September 26, 2015, the Company included the dilutive effects of the Notes in the calculation of diluted net income per common share as the average market price was above the conversion price of the Notes. The dilutive impact of the Notes was based on the difference between the Company's average stock price during the period and the conversion price of the Notes. Upon conversion of the Notes, it is the Company’s intention to pay cash equal to the lesser of the aggregate principal amount or the conversion value of the Notes being converted, therefore, only the conversion spread relating to the Notes would be included in the Company’s diluted earnings per share calculation. The following sets forth the potentially dilutive shares excluded from the computation of the diluted net income (loss) per share because their effect was anti-dilutive (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Stock options 1,834 1 61 7 RSUs 5,475 26 2,454 535 PSUs 905 — 643 97 ESPP shares 1,334 484 638 300 Total 9,548 511 3,796 939

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Sep. 24, 2016
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes In May 2013, the Company issued the Notes, which will mature on June 1, 2018, unless earlier purchased by the Company or converted. Interest is payable semi-annually in arrears on June 1 and December 1 of each year, commencing December 1, 2013. The net proceeds to the Company were approximately $144.5 million . The Notes are governed by an indenture dated as of May 30, 2013 (the "Indenture"), between the Company, as issuer, and U.S. Bank National Association, as trustee. The Notes are unsecured and do not contain any financial covenants or any restrictions on the payment of dividends, the incurrence of senior debt or other indebtedness, or the issuance or repurchase of securities by the Company. Upon conversion, it is the Company's intention to pay cash equal to the lesser of the aggregate principal amount or the conversion value of the Notes. For any remaining conversion obligation, the Company intends to pay cash, shares of common stock or a combination of cash and shares of common stock, at its election. The initial conversion rate is 79.4834 shares of common stock per $1,000 principal amount of Notes, subject to anti-dilution adjustments. The initial conversion price is approximately $12.58 per share of common stock. Throughout the term of the Notes, the conversion rate may be adjusted upon the occurrence of certain events, including for any cash dividends. Holders of the Notes will not receive any cash payment representing accrued and unpaid interest upon conversion of a Note. Accrued but unpaid interest will be deemed to be paid in full upon conversion rather than canceled, extinguished or forfeited. Holders may convert their Notes under the following circumstances: • during any fiscal quarter commencing after the fiscal quarter ended on March 28, 2013 (and only during such fiscal quarter) if the last reported sale price of the 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 on each applicable trading day; • 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; • upon the occurrence of specified corporate events described under the Indenture, such as a consolidation, merger or binding share exchange; or • at any time on or after December 1, 2017 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. If the Company undergoes a fundamental change as defined in the Indenture governing the Notes, holders may require the Company to repurchase for cash all or any portion of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, upon the occurrence of a “make-whole fundamental change” (as defined in the Indenture), the Company may, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its Notes in connection with such make-whole fundamental change. The net carrying amounts of the debt obligation were as follows (in thousands): September 24, 2016 December 26, 2015 Principal $ 150,000 $ 150,000 Unamortized discount (1) (17,565 ) (24,560 ) Unamortized issuance cost (1) (1,511 ) (2,113 ) Net carrying amount $ 130,924 $ 123,327 (1) Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately 20 months . As of September 24, 2016 and December 26, 2015, the carrying amount of the equity component of the Notes was $43.3 million . In accounting for the issuance of the Notes, the Company separated the Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount ("debt discount") is amortized to interest expense over the term of the Notes. In accounting for the issuance costs of $5.5 million related to the Notes, the Company allocated the total amount incurred to the liability and equity components of the Notes based on their relative values. Issuance costs attributable to the liability component were initially recorded as other non-current assets and will be amortized to interest expense over the term of the Notes. ASU 2015-03 requires an entity to present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. The Company adopted ASU 2015-03 during the first quarter of 2016. The December 26, 2015 balance sheet was retrospectively adjusted to reclassify $2.1 million from other non-current assets to a reduction of the Notes payable liability. The issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. Additionally, the Company initially recorded a deferred tax liability of $17.0 million in connection with the issuance of the Notes, and a corresponding reduction in valuation allowance. The impact of both was recorded to stockholders’ equity. The Company determined that the embedded conversion option in the Notes does not require separate accounting treatment as a derivative instrument because it is both indexed to the Company’s own stock and would be classified in stockholder’s equity if freestanding. The following table sets forth total interest expense recognized related to the Notes (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Contractual interest expense $ 656 $ 656 $ 1,969 $ 1,969 Amortization of debt issuance costs 206 186 602 544 Amortization of debt discount 2,391 2,162 6,996 6,328 Total interest expense $ 3,253 $ 3,004 $ 9,567 $ 8,841 The coupon rate is 1.75% . For the three and nine months ended September 24, 2016 and September 26, 2015 , the debt discount and debt issuance costs are amortized, using an annual effective interest rate of 10.23% , to interest expense over the term of the Notes. As of September 24, 2016 , the fair value of the Notes was $156.0 million . The fair value was determined based on the quoted bid price of the Notes in an over-the-counter market on September 23, 2016. The Notes are classified as Level 2 of the fair value hierarchy. During the three months ended September 24, 2016 , the closing price of the Company's common stock did not meet the conversion criteria; therefore, holders of the Notes may not convert their notes during the fourth quarter of 2016. Should the closing price conditions be met during the 30 consecutive trading days prior to the end of the fourth quarter of 2016 or a future quarter, the Notes will be convertible at their holders’ option during the immediately following quarter. Based on the closing price of the Company’s common stock of $8.85 on September 23, 2016, the if-converted value of the Notes did not exceed their principal amount.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 24, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stockholders' Equity	Stockholders’ Equity Stock-based Compensation Plans The Company has stock-based compensation plans pursuant to which the Company has granted stock options, RSUs and PSUs. The Company also has an ESPP for all eligible employees. In February 2016, the Company's board of directors adopted the 2016 Equity Incentive Plan ("2016 Plan") and the Company's stockholders approved the 2016 Plan in May 2016. As of September 24, 2016, the Company reserved a total of 7.2 million shares of common stock for issuance of stock options, RSUs and PSUs to employees, non-employees, consultants and members of the Company's board of directors, pursuant to the 2016 Plan, plus any shares subject to awards granted under the Company’s 2007 Equity Incentive Plan (the “2007 Plan”) that, after the effective date of the 2016 Plan, expire, are forfeited or otherwise terminate without having been exercised in full to the extent such awards were exercisable, and shares issued pursuant to awards granted under the 2007 Plan that, after the effective date of the 2016 Plan, are forfeited to or repurchased by the Company due to failure to vest. The 2016 Plan has a maximum term of 10 years from the date of adoption, or it can be earlier terminated by the Company's board of directors. The 2007 Plan was canceled; however, it continues to govern outstanding grants under the 2007 Plan. The following tables summarize the Company’s equity award activity and related information (in thousands, except per share data): Number of Stock Options Weighted-Average Exercise Price Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 2,511 $ 7.26 $ 28,288 Stock options granted — $ — Stock options exercised (651 ) $ 4.42 $ 4,158 Stock options canceled (26 ) $ 12.38 Outstanding at September 24, 2016 1,834 $ 8.19 $ 1,761 Exercisable at September 24, 2016 1,826 $ 8.19 $ 1,761 Number of Restricted Stock Units Weighted- Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 4,932 $ 12.76 $ 91,285 RSUs granted 2,791 $ 14.32 RSUs released (1,984 ) $ 10.63 $ 23,948 RSUs canceled (263 ) $ 13.74 Outstanding at September 24, 2016 5,476 $ 14.28 $ 48,461 Number of Performance Stock Units Weighted- Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 731 $ 12.35 $ 13,540 PSUs granted 647 $ 15.28 PSUs performance earned (1) 234 $ 12.28 PSUs released (615 ) $ 11.25 $ 8,077 PSUs canceled (92 ) $ 15.21 Outstanding at September 24, 2016 905 $ 14.02 $ 8,008 Expected to vest at September 24, 2016 195 $ 1,725 (1) Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts. The aggregate intrinsic value of unexercised stock options is calculated as the difference between the closing price of the Company’s common stock of $8.85 at September 23, 2016 (the last trading day of the fiscal quarter) and the exercise prices of the underlying stock options. The aggregate intrinsic value of the stock options that have been exercised is calculated as the difference between the fair market value of the common stock at the date of exercise and the exercise price of the underlying stock options. The aggregate intrinsic value of unreleased RSUs and unreleased PSUs is calculated using the closing price of the Company's common stock of $8.85 at September 23, 2016 (the last trading day of the fiscal quarter). The aggregate intrinsic value of RSUs and PSUs released is calculated using the fair market value of the common stock at the date of release. The following table presents total stock-based compensation cost for instruments granted but not yet amortized, net of estimated forfeitures, of the Company’s equity compensation plans as of September 24, 2016 . These costs are expected to be amortized on a straight-line basis over the following weighted-average periods (in thousands, except for weighted-average period): Unrecognized Compensation Expense, Net Weighted- Average Period (in years) Stock options $ 30 1.3 RSUs $ 60,952 2.6 PSUs $ 7,163 1.6 Employee Stock Options The Company did not grant any stock options during the three and nine months ended September 24, 2016. Amortization of stock-based compensation related to stock options in the three and nine months ended September 24, 2016 and September 26, 2015 was insignificant in both periods. Employee Stock Purchase Plan The fair value of the shares was estimated at the date of grant using the following assumptions (expense amounts in thousands): Three Months Ended Nine Months Ended Employee Stock Purchase Plan September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Volatility 67% 39% 56% - 67% 39% - 53% Risk-free interest rate 0.51% 0.26% 0.51% - 0.52% 0.13% - 0.26% Expected life 0.5 years 0.5 years 0.5 years 0.5 years Estimated fair value $3.16 $6.43 $3.16 - $4.53 $5.15 - $6.43 Total stock-based compensation expense $1,565 $1,147 $4,054 $3,275 Restricted Stock Units The Company granted RSUs to employees and members of the Company’s board of directors to receive shares of the Company’s common stock. All RSUs awarded are subject to each individual's continued service to the Company through each applicable vesting date. The Company accounted for the fair value of the RSUs using the closing market price of the Company’s common stock on the date of grant. Amortization of stock-based compensation related to RSUs in the three and nine months ended September 24, 2016 and September 26, 2015 was approximately $7.7 million and $21.4 million , respectively, and $5.6 million and $16.7 million , respectively. Performance Stock Units Pursuant to the 2007 Plan, the Company has granted PSUs to certain of the Company’s executive officers, senior management and employees. All PSUs awarded are subject to each individual's continued service to the Company through each applicable vesting date and if the performance metrics are not met within the time limits specified in the award agreements, the PSUs will be canceled. A number of PSUs granted to the Company’s executive officers and senior management are based on the total shareholder return of the Company's common stock price as compared to the total shareholder return of the S&P North American Technology Multimedia Networking Index ("SPGIIPTR") over the span of one year , two years and three years . The number of shares to be issued upon vesting of these PSUs range from 0 to 2.0 times the target number of PSUs granted depending on the Company’s performance against the SPGIIPTR. The ranges of estimated values of the PSUs granted that are compared to the SPGIIPTR, as well as the assumptions used in calculating these values were based on estimates as follows: 2016 2015 2014 Index SPGIIPTR SPGIIPTR SPGIIPTR Index volatility 18% 18% - 19% 25% Infinera volatility 55% 48% 49% - 50% Risk-free interest rate 0.95% - 1.07% 0.97% - 1.10% 0.66% - 0.71% Correlation with index 0.58 - 0.59 0.52 0.60 Estimated fair value $10.31 - $16.62 $18.08 - $19.29 $6.59 - $7.60 In addition, certain other PSUs granted to the Company’s executive officers, senior management and certain employees will only vest upon the achievement of specific financial or operational performance criteria. The following table summarizes by grant year, the Company’s PSU activity for the nine months ended September 24, 2016 (in thousands): Total Number of Performance Stock Units 2013 2014 2015 2016 Outstanding at December 26, 2015 731 147 260 324 — PSUs granted 647 — — — 647 PSUs performance earned (1) 234 70 53 111 — PSUs released (615 ) (211 ) (179 ) (225 ) — PSUs canceled (92 ) (6 ) (11 ) (62 ) (13 ) Outstanding at September 24, 2016 905 — 123 148 634 (1) Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts. Amortization of stock-based compensation related to PSUs for the three and nine months ended September 24, 2016 was approximately $1.7 million and $4.9 million , respectively, and was approximately $1.6 million and $3.8 million , respectively for the corresponding periods in 2015. Stock-Based Compensation The following tables summarize the effects of stock-based compensation on the Company’s condensed consolidated balance sheets and statements of operations for the periods presented (in thousands): September 24, 2016 December 26, 2015 Stock-based compensation effects in inventory $ 4,378 $ 3,129 Stock-based compensation effects in property, plant and equipment, net $ 74 $ 93 Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Stock-based compensation effects included in net income (loss) before income taxes Cost of revenue $ 756 $ 645 $ 2,175 $ 1,740 Research and development 3,496 2,788 9,721 8,183 Sales and marketing 2,826 2,131 8,006 5,922 General and administration 2,465 1,911 6,850 5,406 $ 9,543 $ 7,475 $ 26,752 $ 21,251 Cost of revenue – amortization from balance sheet (1) 668 976 2,439 2,617 Total stock-based compensation expense $ 10,211 $ 8,451 $ 29,191 $ 23,868 (1) Stock-based compensation expense deferred to inventory and deferred inventory costs in prior periods and recognized in the current period.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 24, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Benefit from income taxes during the three and nine months ended September 24, 2016 was $2.4 million and $0.7 million , respectively, on a pre-tax loss of $13.7 million and pre-tax income of $11.1 million , respectively. This compared to a tax benefit for $0.2 million and tax provision of $1.5 million , respectively, on a pre-tax income of $8.4 million and $40.3 million , respectively, for the three and nine months ended September 26, 2015. The results for the three months ended September 24, 2016 reflect approximately $6.9 million of purchase accounting amortization and other charges related to the acquisition of Transmode, with a corresponding tax benefit of approximately $1.5 million . Exclusive of this tax benefit, provision for income taxes otherwise increased by approximately $2.0 million during the three months ended September 24, 2016 compared to September 26, 2015, which relates to lower forecasted tax expense for the year incurred ratably through the nine months ended September 24, 2016. The results for the nine months ended September 24, 2016 reflected approximately $21.0 million of purchase accounting amortization and other charges related to the acquisition of Transmode, with a corresponding tax benefit of approximately $4.6 million . Exclusive of this tax benefit, provision for income taxes otherwise increased by approximately $1.2 million in the nine months ended September 24, 2016 compared to September 26, 2015, which is attributed to a higher proportion of foreign income earned on a year to date basis related to the Transmode operations and increased spending in certain of the Company's cost-plus foreign subsidiaries. In all periods, the tax expense and benefit projected in the Company's effective tax rate assumptions primarily represents foreign taxes of the Company's overseas subsidiaries compensated on a cost-plus basis, as well as the operating results of Transmode, inclusive of purchase accounting charges and amortization for the three and nine months ended September 24, 2016. Due to the Company's significant U.S. loss carryforward position and corresponding full valuation allowance, the Company has not been subject to federal or state tax on its U.S. income because of the availability of loss carryforwards, with the exception of some state taxes for which the losses are limited. The release of transfer pricing reserves in the future will have a beneficial impact to tax expense, but the timing of the impact depends on factors such as expiration of the statute of limitations or settlements with tax authorities. No significant releases are expected in the near future based on information available at this time. The Company must assess the likelihood that some portion or all of its deferred tax assets will be recovered from future taxable income within the respective jurisdictions. In the past, the Company established a valuation allowance against its deferred tax assets as it determined that its ability to recover the value of these assets did not meet the “more-likely-than-not” standard. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management judgment is required on an on-going basis to determine whether it needs to maintain the valuation allowance recorded against its net deferred tax assets. The Company has been profitable during the nine consecutive quarters between the second quarter of 2014 and the second quarter of 2016. However, in the quarter ending September 24, 2016, the company incurred a net loss. The Company must consider all positive and negative evidence, including its forecasts of taxable income over the applicable carryforward periods, its current financial performance, its market environment, and other factors in evaluating the need for a valuation allowance against its net U.S. deferred tax assets. At September 24, 2016, the Company does not believe that it is more-likely-than-not that it would be able to utilize its deferred tax assets in the foreseeable future. Accordingly, the domestic net deferred tax assets continued to be fully reserved with a valuation allowance. To the extent that the Company determines that deferred tax assets are realizable on a more-likely-than-not basis, and adjustment is needed, that adjustment will be recorded in the period that the determination is made and would generally decrease the valuation allowance and record a corresponding benefit to earnings. On March 30, 2016, FASB issued ASU 2016-09, which the Company early adopted as of June 26, 2016. As a result of the adoption of ASU 2016-09, excess windfall tax benefits and tax deficiencies related to the Company's stock option exercises and vesting of RSUs are recognized as an income tax benefit or expense in its condensed consolidated statements of operations in the period they are deducted on the income tax return. Excess windfall tax benefits and tax deficiencies are therefore not anticipated when determining the annual effective tax rate and are instead recognized in the interim period in which those items occur. The adoption of ASU 2016-09 did not have any material impact on our income tax expense for the three and nine months ended September 24, 2016, primarily due to the Company's valuation allowance position.

Segment Information

Segment Information	9 Months Ended
	Sep. 24, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Company’s Chief Executive Officer ("CEO"). The Company’s CEO reviews financial information presented on a consolidated basis, accompanied by information about revenue by geographic region for purposes of allocating resources and evaluating financial performance. The Company has one business activity. Accordingly, the Company is considered to be in a single reporting segment and operating unit structure. Revenue by geographic region is based on the shipping address of the customer. The following tables set forth revenue and long-lived assets by geographic region (in thousands): Revenue Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Americas: United States $ 104,045 $ 158,845 $ 445,270 $ 440,610 Other Americas 17,390 20,874 31,916 39,944 121,435 179,719 477,186 480,554 Europe, Middle East and Africa 51,940 41,655 176,386 114,163 Asia Pacific and Japan 12,077 11,098 35,520 31,963 Total revenue $ 185,452 $ 232,472 $ 689,092 $ 626,680 Property, plant and equipment, net September 24, 2016 December 26, 2015 United States $ 112,439 $ 102,702 Other Americas 247 173 112,686 102,875 Europe, Middle East and Africa 4,447 5,417 Asia Pacific and Japan 3,004 2,569 Total property, plant and equipment, net $ 120,137 $ 110,861

Guarantees

Guarantees	9 Months Ended
	Sep. 24, 2016
Guarantees [Abstract]
Guarantees	Guarantees Product Warranties The Company warrants that its products will operate substantially in conformity with product specifications. Hardware warranties provide the purchaser with protection in the event that the product does not perform to product specifications. During the warranty period, the purchaser’s sole and exclusive remedy in the event of such defect or failure to perform is limited to the correction of the defect or failure by repair, refurbishment or replacement, at the Company’s sole option and expense. The Company's hardware warranty periods generally range from one to five years from date of acceptance for hardware and the Company's software warranty is 90 days . Upon delivery of the Company's products, the Company provides for the estimated cost to repair or replace products that may be returned under warranty. The hardware warranty accrual is based on actual historical returns and cost of repair experience and the application of those historical rates to the Company's in-warranty installed base. The provision for warranty claims fluctuates depending upon the installed base of products and the failure rates and costs of repair associated with these products under warranty. Furthermore, the Company's costs of repair vary based on repair volume and its ability to repair, rather than replace, defective units. In the event that actual product failure rates and costs to repair differ from the Company's estimates, revisions to the warranty provision are required. In addition, from time to time, specific hardware warranty accruals may be made if unforeseen technical problems arise with specific products. The Company regularly assesses the adequacy of its recorded warranty liabilities and adjusts the amounts as necessary. Activity related to product warranty was as follows (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Beginning balance $ 40,989 $ 28,439 $ 38,844 $ 27,040 Charges to operations 5,196 10,791 19,258 22,158 Utilization (5,002 ) (3,515 ) (13,691 ) (8,336 ) Change in estimate (1) (2,562 ) 1,026 (5,790 ) (4,121 ) Balance at the end of the period $ 38,621 $ 36,741 $ 38,621 $ 36,741 (1) The Company records hardware warranty liabilities based on the latest quality and cost information available as of that date. The changes in estimate shown here are due to changes in overall actual failure rates, the mix of new versus used units related to replacement of failed units, and changes in the estimated cost of repair. As the Company's products mature over time, failure rates and repair costs generally decline leading to favorable changes in warranty reserves. Letters of Credit and Bank Guarantees The Company had $10.1 million of standby letters of credit and bank guarantees outstanding as of September 24, 2016 that consisted of $4.5 million related to property leases, $4.4 million related to customer performance guarantees, and $1.2 million related to value added tax and customs' licenses. The Company had $5.2 million of standby letters of credit and bank guarantees outstanding as of December 26, 2015, respectively. These consisted of $3.1 million related to customer performance guarantees, $1.2 million related to a value added tax and customs' licenses, and $0.9 million related to property leases. As of September 24, 2016 and December 26, 2015, the Company had a line of credit for approximately $1.3 million and $1.5 million , respectively, to support the issuance of letters of credit, of which $0.7 million had been issued and outstanding. The Company has pledged approximately $4.8 million of assets of a subsidiary to secure this line of credit and other obligations as of September 24, 2016 and December 26, 2015.

Litigation and Contingencies

Litigation and Contingencies	9 Months Ended
	Sep. 24, 2016
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingencies	Litigation and Contingencies From time to time, the Company is subject to various legal proceedings, claims and litigation arising in the ordinary course of business. While the outcome of these matters is currently not determinable, the Company does not expect that the ultimate costs to resolve these matters will have a material effect on its consolidated financial position, results of operations or cash flows. The Company is subject to the possibility of various losses arising in the ordinary course of business. These may relate to disputes, litigation and other legal actions. In the preparation of its quarterly and annual financial statements, the Company considers the likelihood of loss or the incurrence of a liability, including whether it is probable, reasonably possible or remote that a liability has been incurred, as well as the Company’s ability to reasonably estimate the amount of loss, in determining loss contingencies. In accordance with U.S. GAAP, an estimated loss contingency is accrued when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information to determine whether any accruals should be adjusted and whether new accruals are required. As of September 24, 2016, the Company has accrued the estimated liabilities associated with the Company's potential loss contingencies. Intellectual Property Indemnification The Company has agreed to indemnify certain customers for claims made against the Company’s products, where such claims allege infringement of third party intellectual property rights, including, but not limited to, patents, registered trademarks, and/or copyrights. Under the aforementioned indemnification clauses, the Company may be obligated to defend the customer and pay for the damages awarded against the customer under an infringement claim as well as the customer’s attorneys’ fees and costs. The Company’s indemnification obligations generally do not expire after termination or expiration of the agreement containing the indemnification obligation. In certain cases, there are limits on and exceptions to the Company’s potential liability for indemnification. Although historically the Company has not made significant payments under these indemnification obligations, the Company cannot estimate the amount of potential future payments, if any, that it might be required to make as a result of these agreements. The maximum potential amount of any future payments that the Company could be required to make under these indemnification obligations could be significant.

Basis of Presentation and Sig23

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 24, 2016
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update 2016-15, "Statement of Cash Flows (Topic 320): Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15"), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain transactions are presented and classified in the statement of cash flows. This guidance is effective for the Company in its first quarter of fiscal 2018 and will be applied on a retrospective basis. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its condensed consolidated financial statements. In June 2016, the FASB issued Accounting Standards Update 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"), which requires measurement and recognition of expected credit losses for financial assets held. This guidance is effective for the Company in its first quarter of fiscal 2020 and early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-13 will have on its condensed consolidated financial statements. In May 2016, the FASB issued Accounting Standards Update 2016-11, "Revenue Recognition (Topic 605) and Derivatives and Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting (SEC Update)" ("ASU 2016-11"), which rescinds various standards codified as part of Topic 605, Revenue Recognition in relation to the future adoption of Topic 606. These rescissions include changes to topics pertaining to revenue and expense recognition for freight services in process, accounting for shipping and handling fees and costs, and accounting for consideration given by a vendor to a customer. This guidance is effective for the Company in its first quarter of fiscal 2018 and early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-11 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, which includes provisions intended to simplify various aspects related to how share-based payments are accounted for and presented in the financial statements, including the income tax effects of share-based payments and accounting for forfeitures. ASU 2016-09 requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows, and allows for an accounting policy election to either estimate the number of forfeitures (current U.S. GAAP) or account for forfeitures when they occur, amongst other provisions. This standard provides for prospective, retrospective, or modified retrospective adoption of each of the changes. ASU 2016-09 is effective for the Company in its first quarter of fiscal 2017 and early adoption is permitted. The Company elected to early adopt ASU 2016-09 as of its third fiscal quarter beginning on June 26, 2016. The Company also elected to change its accounting policy to account for forfeitures when they occur on a modified retrospective basis. The adoption of ASU 2016-09 and the change in the Company’s accounting policy resulted in a $0.2 million increase to additional paid-in capital and accumulated deficit as of December 26, 2015. The Company also recorded $0.3 million of stock-based compensation expense during the three months ended September 24, 2016 to true-up for the differential between the amount of stock-based compensation cost previously recorded for the first six months ended June 25, 2016 and the amount that would have been recorded without assuming forfeitures. Additionally, the Company adopted the change in presentation in the condensed consolidated statement of cash flows related to excess tax benefits on a prospective basis. Accordingly, prior periods have not been adjusted. There was no impact for the change in presentation in the condensed consolidated statement of cash flows related to statutory tax withholding requirements as the Company has historically classified the statutory tax withholding as a financing activity in its consolidated statement of cash flows. In February 2016, the FASB issued Accounting Standards Update 2016-02, "Leases (Topic 842)" ("ASU 2016-02"), which amends the existing accounting standards for leases. The new standard requires lessees to record a right-of-use asset and a corresponding lease liability on the balance sheet (with the exception of short-term leases). For lessees, leases will continue to be classified as either operating or financing in the income statement. This guidance is effective for the Company in its first quarter of fiscal 2019 and early adoption is permitted. ASU 2016-02 is required to be applied with a modified retrospective approach and requires application of the new standard at the beginning of the earliest comparative period presented. The Company is currently evaluating the impact the adoption of ASU 2016-02 will have on its consolidated financial statements. In September 2015, the FASB issued Accounting Standards Update 2015-16, "Business Combinations and Simplifying the Accounting for Measurement-Period Adjustments" ("ASU 2015-16"), which eliminates the requirement for an acquirer in a business combination to account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The Company adopted ASU 2015-16 during the first quarter of fiscal 2016. The Company's adoption of ASU 2015-16 had no impact on the Company's financial position, results of operations or cash flow. In July 2015, the FASB issued Accounting Standards Update 2015-11, "Simplifying the Measurement of Inventory" ("ASU 2015-11"), to simplify the guidance on the subsequent measurement of inventory, excluding inventory measured using last-in, first-out or the retail inventory method. Under ASU 2015-11, inventory should be at the lower of cost and net realizable value. This guidance is effective for the Company in its first quarter of fiscal 2017 and early adoption permitted. The Company is currently evaluating the impact the adoption of ASU 2015-11 will have on its consolidated financial statements. In April 2015, the FASB issued Accounting Standards Update 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03"), which changes the presentation of debt issuance costs in financial statements. ASU 2015-03 requires an entity to present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs will continue to be reported as interest expense. The Company adopted ASU 2015-03 during the first quarter of fiscal 2016. The December 26, 2015 balance sheet was retrospectively adjusted to reclassify $2.1 million from other non-current assets to a reduction of the Notes payable liability. In May 2014, the FASB issued Accounting Standards Update 2014-09, "Revenue from Contracts from Customers" ("ASU 2014-09"), which creates a single, joint revenue standard that is consistent across all industries and markets for companies that prepare their financial statements in accordance with GAAP. Under ASU 2014-09, an entity is required to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services. In July 2015, the FASB decided to delay the effective date of the new revenue standard by one year. In April 2016, the FASB issued Accounting Standards Update 2016-10, "Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing," which clarifies the implementation guidance on identifying performance obligations and licensing. In May 2016, the FASB issued Accounting Standards Update 2016-12, "Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients," which amends the guidance on collectability, noncash consideration, presentation of sales tax and transition. These standards will be effective for the Company's first quarter of 2018. The Company is currently evaluating the impact of these new standards on its consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 24, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables represent the Company’s fair value hierarchy for its assets and liabilities measured at fair value on a recurring basis (in thousands): As of September 24, 2016 As of December 26, 2015 Fair Value Measured Using Fair Value Measured Using Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Money market funds $ 35,629 $ — $ — $ 35,629 $ 37,829 $ — $ — $ 37,829 Certificates of deposit — 2,602 — 2,602 — 5,001 — 5,001 Commercial paper — 40,325 — 40,325 — 10,997 — 10,997 Corporate bonds — 105,160 — 105,160 — 163,400 — 163,400 U.S. agency notes — 9,782 — 9,782 — 10,717 — 10,717 U.S. treasuries 56,209 — — 56,209 24,851 — — 24,851 Foreign currency exchange forward contracts — 208 — 208 — 490 — 490 Total assets $ 91,838 $ 158,077 $ — $ 249,915 $ 62,680 $ 190,605 $ — $ 253,285 Liabilities Foreign currency exchange forward contracts $ — $ (263 ) $ — $ (263 ) $ — $ (44 ) $ — $ (44 )
Investments at Fair Value	Investments at fair value were as follows (in thousands): September 24, 2016 Adjusted Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Money market funds $ 35,629 $ — $ — $ 35,629 Certificates of deposit 2,600 2 — 2,602 Commercial paper 40,340 — (15 ) 40,325 Corporate bonds 105,215 21 (76 ) 105,160 U.S. agency notes 9,787 — (5 ) 9,782 U.S. treasuries 56,168 47 (6 ) 56,209 Total available-for-sale investments $ 249,739 $ 70 $ (102 ) $ 249,707 December 26, 2015 Adjusted Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Money market funds $ 37,829 $ — $ — $ 37,829 Certificates of deposit 5,000 1 — 5,001 Commercial paper 10,997 — — 10,997 Corporate bonds 163,797 — (397 ) 163,400 U.S. agency notes 10,786 — (69 ) 10,717 U.S. treasuries 24,894 — (43 ) 24,851 Total available-for-sale investments $ 253,303 $ 1 $ (509 ) $ 252,795

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 24, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments not Designated as Hedging Instruments	The fair value of derivative instruments in the Company’s condensed consolidated balance sheets was as follows (in thousands): As of September 24, 2016 As of December 26, 2015 Gross Notional (1) Prepaid Expense and Other Assets Other Accrued Liabilities Gross Notional (1) Prepaid Expense and Other Assets Other Accrued Liabilities Foreign currency exchange forward contracts Related to euro denominated receivables $ 24,207 $ — $ (262 ) $ 46,753 $ 319 $ (44 ) Related to British pound denominated receivables $ 3,749 208 — $ 6,686 171 — Related to restricted cash $ 258 — (1 ) $ 252 — — $ 208 $ (263 ) $ 490 $ (44 ) (1) Represents the face amounts of forward contracts that were outstanding as of the period noted.

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 24, 2016
Business Combinations [Abstract]
Schedule of Business Acquisitions by Acquisition, Equity Interest Issued or Issuable	The Company has accounted for this transaction as a business combination in exchange for total consideration of $350.6 million , which consisted of the following (in thousands, except shares): Cash $ 181,133 Common stock (7.9 million shares) 169,507 Total $ 350,640
Schedule of Business Acquisitions, by Acquisition	The following table summarizes the Company’s allocation of the purchase consideration based on the fair value of assets acquired and liabilities assumed as of the Acquisition Date (in thousands): Amounts Recognized as of Acquisition Date Measurement Period Adjustments Total Cash $ 36,688 $ — $ 36,688 Accounts receivable 16,183 — 16,183 Inventory 19,886 — 19,886 Other assets 8,320 — 8,320 Intangible assets, net 161,845 — 161,845 Goodwill 187,220 669 187,889 Current liabilities (24,320 ) (800 ) (25,120 ) Deferred tax liabilities (39,221 ) 131 (39,090 ) Long-term liabilities (589 ) — (589 ) Noncontrolling interest (15,372 ) — (15,372 ) Total net assets $ 350,640 $ — $ 350,640
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	The following table presents details of the identified intangible assets acquired at the Acquisition Date (in thousands): Fair Value Estimated Useful Life (Years) Trade name $ 234 0.5 Customer relationships 49,033 8 Developed technology 92,450 5 In-process technology 20,128 N/A Total $ 161,845
Schedule of Indefinite-lived Intangible Assets Acquired as Part of Business Combination	The following table presents details of the identified intangible assets acquired at the Acquisition Date (in thousands): Fair Value Estimated Useful Life (Years) Trade name $ 234 0.5 Customer relationships 49,033 8 Developed technology 92,450 5 In-process technology 20,128 N/A Total $ 161,845
Noncontrolling Interest Rollfoward	Noncontrolling interest was as follows (in thousands): September 24, 2016 December 26, 2015 Beginning noncontrolling interest $ 14,910 $ — Noncontrolling interest investment — 15,373 Acquisition of noncontrolling interest (14,407 ) — Loss attributable to noncontrolling interest (503 ) (463 ) Ending noncontrolling interest $ — $ 14,910

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 24, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table presents details of the Company’s goodwill during the nine months ended September 24, 2016 (in thousands): Balance as of December 26, 2015 $ 191,560 Foreign currency translation adjustments (3,633 ) Accumulated impairment loss — Balance as of September 24, 2016 $ 187,927
Schedule of Finite-Lived Intangible Assets	The following tables present details of the Company’s intangible assets as of September 24, 2016 and December 26, 2015 (in thousands): September 24, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Useful Life (In Years) Intangible assets with finite lives: Trade names $ 234 $ (234 ) $ — — Customer relationships 49,042 (6,753 ) 42,289 6.9 Developed technology 100,285 (21,213 ) 79,072 4.0 Other intangible assets 819 (554 ) 265 4.9 Total intangible assets with finite lives $ 150,380 $ (28,754 ) $ 121,626 5.0 In-process technology 12,313 — 12,313 Total intangible assets $ 162,693 $ (28,754 ) $ 133,939 December 26, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Useful Life (In Years) Intangible assets with finite lives: Trade names $ 239 $ (168 ) $ 71 0.2 Customer relationships 49,991 (2,197 ) 47,794 7.7 Developed technology 94,256 (6,629 ) 87,627 4.6 Other intangible assets 819 (513 ) 306 5.6 Total intangible assets with finite lives $ 145,305 $ (9,507 ) $ 135,798 5.7 In-process technology 20,521 — 20,521 Total intangible assets $ 165,826 $ (9,507 ) $ 156,319
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes the Company’s estimated future amortization expense of intangible assets with finite lives as of September 24, 2016 (in thousands): Fiscal Years Total Remainder of 2016 2017 2018 2019 2020 2021 and Thereafter Total future amortization expense $ 121,626 $ 6,612 $ 26,487 $ 26,487 $ 25,879 $ 18,886 $ 17,275

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 24, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Details of Selected Balance Sheet Items	The following table provides details of selected balance sheet items (in thousands): September 24, 2016 December 26, 2015 Inventory: Raw materials $ 37,199 $ 27,879 Work in process 65,540 52,599 Finished goods 128,789 94,221 Total inventory $ 231,528 $ 174,699 Property, plant and equipment, net: Computer hardware $ 12,741 $ 11,097 Computer software (1) 26,718 22,548 Laboratory and manufacturing equipment 215,690 189,168 Furniture and fixtures 2,060 1,897 Leasehold improvements 43,048 38,946 Construction in progress 27,976 31,060 Subtotal $ 328,233 $ 294,716 Less accumulated depreciation and amortization (208,096 ) (183,855 ) Total property, plant and equipment, net $ 120,137 $ 110,861 Accrued expenses: Loss contingency related to non-cancelable purchase commitments $ 6,293 $ 6,821 Professional and other consulting fees 4,198 5,363 Taxes payable 4,532 3,295 Royalties 5,376 4,290 Other accrued expenses 17,458 13,967 Total accrued expenses $ 37,857 $ 33,736 (1) Included in computer software at September 24, 2016 and December 26, 2015 were $9.1 million and $7.9 million , respectively, related to an ERP system that the Company implemented. The unamortized ERP costs at September 24, 2016 and December 26, 2015 were $4.3 million and $4.0 million , respectively

Accumulated Other Comprehensi29

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 24, 2016
Equity [Abstract]
Summary of Changes in Accumulated Other Comprehensive Income (Loss)	The following table sets forth the changes in accumulated other comprehensive income (loss) by component for the nine months ended September 24, 2016 (in thousands): Unrealized Gain (Loss) on Other Available-for-Sale Securities Foreign Currency Translation Accumulated Tax Effect Total Balance at December 26, 2015 $ (506 ) $ 2,389 $ (760 ) $ 1,123 Net current-period other comprehensive income (loss) 476 (7,609 ) — (7,133 ) Balance at September 24, 2016 $ (30 ) $ (5,220 ) $ (760 ) $ (6,010 )

Basic and Diluted Net Income 30

Basic and Diluted Net Income (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 24, 2016
Earnings Per Share [Abstract]
Computation of Net Income (Loss) Per Common Share Basic and Diluted	The following table sets forth the computation of net income (loss) per common share – basic and diluted (in thousands, except per share amounts): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Numerator: Net income (loss) attributable to Infinera Corporation $ (11,172 ) $ 8,510 $ 12,326 $ 38,782 Denominator: Basic weighted average common shares outstanding 143,850 134,834 142,350 131,007 Effect of dilutive securities: Employee equity plans — 5,397 2,580 5,911 Assumed conversion of convertible senior notes from conversion spread — 5,069 991 4,164 Diluted weighted average common shares outstanding 143,850 145,300 145,921 141,082 Net income (loss) per common share attributable to Infinera Corporation Basic $ (0.08 ) $ 0.06 $ 0.09 $ 0.30 Diluted $ (0.08 ) $ 0.06 $ 0.08 $ 0.27
Antidilutive Shares Excluded from Computation of Diluted Net Income (Loss) Per Share	The following sets forth the potentially dilutive shares excluded from the computation of the diluted net income (loss) per share because their effect was anti-dilutive (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Stock options 1,834 1 61 7 RSUs 5,475 26 2,454 535 PSUs 905 — 643 97 ESPP shares 1,334 484 638 300 Total 9,548 511 3,796 939

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Sep. 24, 2016
Debt Disclosure [Abstract]
Components of Convertible Senior Notes	The net carrying amounts of the debt obligation were as follows (in thousands): September 24, 2016 December 26, 2015 Principal $ 150,000 $ 150,000 Unamortized discount (1) (17,565 ) (24,560 ) Unamortized issuance cost (1) (1,511 ) (2,113 ) Net carrying amount $ 130,924 $ 123,327 (1) Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately 20 months .
Interest expense recognized related to Notes	The following table sets forth total interest expense recognized related to the Notes (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Contractual interest expense $ 656 $ 656 $ 1,969 $ 1,969 Amortization of debt issuance costs 206 186 602 544 Amortization of debt discount 2,391 2,162 6,996 6,328 Total interest expense $ 3,253 $ 3,004 $ 9,567 $ 8,841

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 24, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Company's Equity Award Activity - Options	The following tables summarize the Company’s equity award activity and related information (in thousands, except per share data): Number of Stock Options Weighted-Average Exercise Price Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 2,511 $ 7.26 $ 28,288 Stock options granted — $ — Stock options exercised (651 ) $ 4.42 $ 4,158 Stock options canceled (26 ) $ 12.38 Outstanding at September 24, 2016 1,834 $ 8.19 $ 1,761 Exercisable at September 24, 2016 1,826 $ 8.19 $ 1,761
Summary of Company's Equity Award Activity - RSUs	Number of Restricted Stock Units Weighted- Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 4,932 $ 12.76 $ 91,285 RSUs granted 2,791 $ 14.32 RSUs released (1,984 ) $ 10.63 $ 23,948 RSUs canceled (263 ) $ 13.74 Outstanding at September 24, 2016 5,476 $ 14.28 $ 48,461
Summary of Company's Equity Award Activity - PSUs	Number of Performance Stock Units Weighted- Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Outstanding at December 26, 2015 731 $ 12.35 $ 13,540 PSUs granted 647 $ 15.28 PSUs performance earned (1) 234 $ 12.28 PSUs released (615 ) $ 11.25 $ 8,077 PSUs canceled (92 ) $ 15.21 Outstanding at September 24, 2016 905 $ 14.02 $ 8,008 Expected to vest at September 24, 2016 195 $ 1,725 (1) Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.
Total Stock Based Compensation Cost for Instruments Granted but Not Yet Amortized	The following table presents total stock-based compensation cost for instruments granted but not yet amortized, net of estimated forfeitures, of the Company’s equity compensation plans as of September 24, 2016 . These costs are expected to be amortized on a straight-line basis over the following weighted-average periods (in thousands, except for weighted-average period): Unrecognized Compensation Expense, Net Weighted- Average Period (in years) Stock options $ 30 1.3 RSUs $ 60,952 2.6 PSUs $ 7,163 1.6
Estimated Fair Value of ESPP Shares	The fair value of the shares was estimated at the date of grant using the following assumptions (expense amounts in thousands): Three Months Ended Nine Months Ended Employee Stock Purchase Plan September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Volatility 67% 39% 56% - 67% 39% - 53% Risk-free interest rate 0.51% 0.26% 0.51% - 0.52% 0.13% - 0.26% Expected life 0.5 years 0.5 years 0.5 years 0.5 years Estimated fair value $3.16 $6.43 $3.16 - $4.53 $5.15 - $6.43 Total stock-based compensation expense $1,565 $1,147 $4,054 $3,275
Schedule of Share-based Payment Award, Valuation Assumptions	The ranges of estimated values of the PSUs granted that are compared to the SPGIIPTR, as well as the assumptions used in calculating these values were based on estimates as follows: 2016 2015 2014 Index SPGIIPTR SPGIIPTR SPGIIPTR Index volatility 18% 18% - 19% 25% Infinera volatility 55% 48% 49% - 50% Risk-free interest rate 0.95% - 1.07% 0.97% - 1.10% 0.66% - 0.71% Correlation with index 0.58 - 0.59 0.52 0.60 Estimated fair value $10.31 - $16.62 $18.08 - $19.29 $6.59 - $7.60
Schedule Of Nonvested Performance Based Units Activity By Grant Year	The following table summarizes by grant year, the Company’s PSU activity for the nine months ended September 24, 2016 (in thousands): Total Number of Performance Stock Units 2013 2014 2015 2016 Outstanding at December 26, 2015 731 147 260 324 — PSUs granted 647 — — — 647 PSUs performance earned (1) 234 70 53 111 — PSUs released (615 ) (211 ) (179 ) (225 ) — PSUs canceled (92 ) (6 ) (11 ) (62 ) (13 ) Outstanding at September 24, 2016 905 — 123 148 634 (1) Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.
Summary of Effects of Stock-Based Compensation on Company's Balance Sheets and Statements of Operations	The following tables summarize the effects of stock-based compensation on the Company’s condensed consolidated balance sheets and statements of operations for the periods presented (in thousands): September 24, 2016 December 26, 2015 Stock-based compensation effects in inventory $ 4,378 $ 3,129 Stock-based compensation effects in property, plant and equipment, net $ 74 $ 93 Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Stock-based compensation effects included in net income (loss) before income taxes Cost of revenue $ 756 $ 645 $ 2,175 $ 1,740 Research and development 3,496 2,788 9,721 8,183 Sales and marketing 2,826 2,131 8,006 5,922 General and administration 2,465 1,911 6,850 5,406 $ 9,543 $ 7,475 $ 26,752 $ 21,251 Cost of revenue – amortization from balance sheet (1) 668 976 2,439 2,617 Total stock-based compensation expense $ 10,211 $ 8,451 $ 29,191 $ 23,868 (1) Stock-based compensation expense deferred to inventory and deferred inventory costs in prior periods and recognized in the current period.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 24, 2016
Segment Reporting [Abstract]
Revenue and Long-Lived Assets by Geographic Region	Revenue by geographic region is based on the shipping address of the customer. The following tables set forth revenue and long-lived assets by geographic region (in thousands): Revenue Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Americas: United States $ 104,045 $ 158,845 $ 445,270 $ 440,610 Other Americas 17,390 20,874 31,916 39,944 121,435 179,719 477,186 480,554 Europe, Middle East and Africa 51,940 41,655 176,386 114,163 Asia Pacific and Japan 12,077 11,098 35,520 31,963 Total revenue $ 185,452 $ 232,472 $ 689,092 $ 626,680
Property, Plant and Equipment, Net	Property, plant and equipment, net September 24, 2016 December 26, 2015 United States $ 112,439 $ 102,702 Other Americas 247 173 112,686 102,875 Europe, Middle East and Africa 4,447 5,417 Asia Pacific and Japan 3,004 2,569 Total property, plant and equipment, net $ 120,137 $ 110,861

Guarantees (Tables)

Guarantees (Tables)	9 Months Ended
	Sep. 24, 2016
Guarantees [Abstract]
Activity Related to Product Warranty	Activity related to product warranty was as follows (in thousands): Three Months Ended Nine Months Ended September 24, 2016 September 26, 2015 September 24, 2016 September 26, 2015 Beginning balance $ 40,989 $ 28,439 $ 38,844 $ 27,040 Charges to operations 5,196 10,791 19,258 22,158 Utilization (5,002 ) (3,515 ) (13,691 ) (8,336 ) Change in estimate (1) (2,562 ) 1,026 (5,790 ) (4,121 ) Balance at the end of the period $ 38,621 $ 36,741 $ 38,621 $ 36,741 (1) The Company records hardware warranty liabilities based on the latest quality and cost information available as of that date. The changes in estimate shown here are due to changes in overall actual failure rates, the mix of new versus used units related to replacement of failed units, and changes in the estimated cost of repair. As the Company's products mature over time, failure rates and repair costs generally decline leading to favorable changes in warranty reserves.

Basis of Presentation and Sig35

Basis of Presentation and Significant Accounting Polices (Details)	3 Months Ended		9 Months Ended
	Sep. 24, 2016USD ($)customer	Sep. 26, 2015USD ($)customer	Sep. 24, 2016USD ($)customer	Sep. 26, 2015USD ($)customer	May 30, 2013USD ($)
Concentration Risk [Line Items]
Cost of revenue	$ (100,850,000)	$ (129,667,000)	$ (364,406,000)	$ (338,967,000)
Customers accounting for a significant portion of revenue | customer	2	2	2	2
Sales revenue, net | Customer One | Customer concentration risk
Concentration Risk [Line Items]
Concentration risk	16.00%	26.00%	16.00%	18.00%
Sales revenue, net | Customer Two | Customer concentration risk
Concentration Risk [Line Items]
Concentration risk	12.00%	16.00%	10.00%	15.00%
Transmode | Scenario, adjustment
Concentration Risk [Line Items]
Cost of revenue	$ 2,000,000		$ 2,000,000
1.75% Convertible Senior Notes Due June 1, 2018
Concentration Risk [Line Items]
Principal amount					$ 150,000,000
Debt instrument interest percentage	1.75%		1.75%		1.75%

Recent Accounting Pronounceme36

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015	Dec. 26, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Additional paid-in capital	$ 1,341,501		$ 1,341,501		$ 1,300,301
Accumulated deficit	527,322		527,322		539,413
Increase to current quarter expense for catch-up	10,211	$ 8,451	$ 29,191	$ 23,868
Accounting Standards Update 2016-09
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated deficit					200
Other noncurrent assets | Accounting Standards Update 2015-03
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Debt issuance costs					(2,100)
Long-term debt | Accounting Standards Update 2015-03
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Debt issuance costs					2,100
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Additional paid-in capital					$ 200
Increase to current quarter expense for catch-up	$ 300

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair value, measurements, recurring - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Assets
Total assets	$ 249,915	$ 253,285
Foreign currency exchange forward contracts
Assets
Total assets	208	490
Liabilities
Total liabilities	(263)	(44)
Money market funds
Assets
Total assets	35,629	37,829
Certificates of deposit
Assets
Total assets	2,602	5,001
Commercial paper
Assets
Total assets	40,325	10,997
Corporate bonds
Assets
Total assets	105,160	163,400
U.S. agency notes
Assets
Total assets	9,782	10,717
U.S. treasuries
Assets
Total assets	56,209	24,851
Level 1
Assets
Total assets	91,838	62,680
Level 1 | Foreign currency exchange forward contracts
Assets
Total assets	0	0
Liabilities
Total liabilities	0	0
Level 1 | Money market funds
Assets
Total assets	35,629	37,829
Level 1 | Certificates of deposit
Assets
Total assets	0	0
Level 1 | Commercial paper
Assets
Total assets	0	0
Level 1 | Corporate bonds
Assets
Total assets	0	0
Level 1 | U.S. agency notes
Assets
Total assets	0	0
Level 1 | U.S. treasuries
Assets
Total assets	56,209	24,851
Level 2
Assets
Total assets	158,077	190,605
Level 2 | Foreign currency exchange forward contracts
Assets
Total assets	208	490
Liabilities
Total liabilities	(263)	(44)
Level 2 | Money market funds
Assets
Total assets	0	0
Level 2 | Certificates of deposit
Assets
Total assets	2,602	5,001
Level 2 | Commercial paper
Assets
Total assets	40,325	10,997
Level 2 | Corporate bonds
Assets
Total assets	105,160	163,400
Level 2 | U.S. agency notes
Assets
Total assets	9,782	10,717
Level 2 | U.S. treasuries
Assets
Total assets	0	0
Level 3
Assets
Total assets	0	0
Level 3 | Foreign currency exchange forward contracts
Assets
Total assets	0	0
Liabilities
Total liabilities	0	0
Level 3 | Money market funds
Assets
Total assets	0	0
Level 3 | Certificates of deposit
Assets
Total assets	0	0
Level 3 | Commercial paper
Assets
Total assets	0	0
Level 3 | Corporate bonds
Assets
Total assets	0	0
Level 3 | U.S. agency notes
Assets
Total assets	0	0
Level 3 | U.S. treasuries
Assets
Total assets	$ 0	$ 0

Fair Value Measurements - Inves

Fair Value Measurements - Investments at Fair Value (Details) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	$ 249,739	$ 253,303
Gross Unrealized Gains	70	1
Gross Unrealized Losses	(102)	(509)
Fair Value	249,707	252,795
Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	35,629	37,829
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	35,629	37,829
Certificates of deposit
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	2,600	5,000
Gross Unrealized Gains	2	1
Gross Unrealized Losses	0	0
Fair Value	2,602	5,001
Commercial paper
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	40,340	10,997
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(15)	0
Fair Value	40,325	10,997
Corporate bonds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	105,215	163,797
Gross Unrealized Gains	21	0
Gross Unrealized Losses	(76)	(397)
Fair Value	105,160	163,400
U.S. agency notes
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	9,787	10,786
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(5)	(69)
Fair Value	9,782	10,717
U.S. treasuries
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	56,168	24,894
Gross Unrealized Gains	47	0
Gross Unrealized Losses	(6)	(43)
Fair Value	$ 56,209	$ 24,851

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 24, 2016	Dec. 26, 2015
Fair Value Disclosures [Abstract]
Available-for-sale investments	24 months
Cash	$ 90.4	$ 98.4

Cost-method Investments - Addit

Cost-method Investments - Additional Information (Details)	Sep. 20, 2016USD ($)	Sep. 24, 2016USD ($)company	Sep. 26, 2015USD ($)	Dec. 26, 2015USD ($)
Gain (Loss) on Investments [Line Items]
Purchase of cost-method investment		$ 5,000,000	$ 0
Cost-method investment, total		19,500,000		$ 14,500,000
Cost-method Investments
Gain (Loss) on Investments [Line Items]
Purchase of cost-method investment	$ 5,000,000
Cost-method investment, preferred stock warrant issued	$ 10,000,000
Cost-method investment, total		$ 19,500,000
Number of privately-held companies | company		2
Less than percent of voting securities		20.00%
Impairment charge on cost-method investments		$ 0

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Before-tax effect of foreign currency exchange forward contracts not designated as hedging instruments, gain (loss)	$ (0.2)	$ 0.3	$ (0.8)	$ (3.1)

Derivative Instruments - Fair V

Derivative Instruments - Fair Value of Derivative Instruments Not Designated as Hedging Activities (Details) - USD ($)		Sep. 24, 2016	Dec. 26, 2015
Derivative [Line Items]
Prepaid expenses and other current assets		$ 30,520,000	$ 29,511,000
Not designated as hedging instrument
Derivative [Line Items]
Prepaid expenses and other current assets		208,000	490,000
Other accrued liabilities		(263,000)	(44,000)
Not designated as hedging instrument | Related to euro denominated receivables
Derivative [Line Items]
Forward contract notional amount	[1]	24,207,000	46,753,000
Prepaid expenses and other current assets		0	319,000
Other accrued liabilities		(262,000)	(44,000)
Not designated as hedging instrument | Related to British pound denominated receivables
Derivative [Line Items]
Forward contract notional amount	[1]	3,749,000	6,686,000
Prepaid expenses and other current assets		208,000	171,000
Other accrued liabilities		0	0
Not designated as hedging instrument | Related to restricted cash
Derivative [Line Items]
Forward contract notional amount	[1]	258,000	252,000
Prepaid expenses and other current assets		0	0
Other accrued liabilities		$ (1,000)	$ 0
[1]	Represents the face amounts of forward contracts that were outstanding as of the period noted.

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Thousands, shares in Millions	Sep. 24, 2016	Aug. 20, 2015	Aug. 31, 2016	Sep. 24, 2016	Sep. 26, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Noncontrolling interest	$ 0			$ 0			$ 14,910	$ 0
Undisputed purchase price paid				16,771	$ 0
Security pledge associated with Squeeze-out Proceedings				$ 5,921	$ 0
Transmode
Business Acquisition [Line Items]
Percentage of acquiree common shares acquired		95.80%
Noncontrolling interest		$ 15,372
Undisputed purchase price paid			$ 16,800
Security pledge associated with Squeeze-out Proceedings	$ 5,900
Total consideration transfered		$ 350,640
Transmode | Scenario, forecast
Business Acquisition [Line Items]
Percentage of acquiree common shares acquired						4.20%
Remaining acquiree shares (in shares)						1.2

Business Combination Total Cons

Business Combination Total Consideration For Acquisition (Details) - Transmode $ in Thousands, shares in Millions	Aug. 20, 2015USD ($)shares
Business Acquisition [Line Items]
Cash	$ 181,133
Common stock (7.9 million shares)	169,507
Total	$ 350,640
Common shares issued in acquisition (in shares) | shares	7.9

Business Combination Allocation

Business Combination Allocation Of Purchase Consideration (Details) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015	Aug. 20, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 187,927	$ 191,560
Noncontrolling interest	$ 0	$ (14,910)		$ 0
Transmode
Business Acquisition [Line Items]
Cash			$ 36,688
Accounts receivable			16,183
Inventory			19,886
Other assets			8,320
Intangible assets, net			161,845
Goodwill			187,889
Current liabilities			(25,120)
Deferred tax liabilities			(39,090)
Long-term liabilities			(589)
Noncontrolling interest			(15,372)
Total net assets			350,640
Scenario, previously reported | Transmode
Business Acquisition [Line Items]
Cash			36,688
Accounts receivable			16,183
Inventory			19,886
Other assets			8,320
Intangible assets, net			161,845
Goodwill			187,220
Current liabilities			(24,320)
Deferred tax liabilities			(39,221)
Long-term liabilities			(589)
Noncontrolling interest			(15,372)
Total net assets			350,640
Scenario, adjustment | Transmode
Business Acquisition [Line Items]
Cash			0
Accounts receivable			0
Inventory			0
Other assets			0
Intangible assets, net			0
Goodwill			669
Current liabilities			(800)
Deferred tax liabilities			131
Long-term liabilities			0
Noncontrolling interest			0
Total net assets			$ 0

Business Combination Intangible

Business Combination Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Aug. 20, 2015	Sep. 24, 2016	Dec. 26, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets gross		$ 162,693	$ 165,826
Estimated useful life (in years)		5 years	5 years 8 months 16 days
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)		0 days	2 months 12 days
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)		6 years 10 months 24 days	7 years 8 months 12 days
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)		4 years	4 years 7 months 24 days
Transmode
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets gross	$ 161,845
Transmode | In-process technology
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets acquired	20,128
Transmode | Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Finite lived intangible assets acquired	$ 234
Estimated useful life (in years)	6 months
Transmode | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite lived intangible assets acquired	$ 49,033
Estimated useful life (in years)	8 years
Transmode | Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite lived intangible assets acquired	$ 92,450
Estimated useful life (in years)	5 years

Business Combination Noncontrol

Business Combination Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015	Dec. 26, 2015
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning noncontrolling interest			$ 14,910	$ 0	$ 0
Less: Loss attributable to noncontrolling interest	$ (125)	$ 0	(503)	$ 0	(463)
Ending noncontrolling interest	$ 0		0		14,910
Noncontrolling Interest
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest investment			0		15,373
Acquisition of noncontrolling interest			$ (14,407)		$ 0

Goodwill and Intangible Asset48

Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015	Dec. 26, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 6,700	$ 2,600	$ 19,800	$ 2,600
In-process technology
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 12,313		12,313		$ 20,521
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, period increase (decrease)			$ 7,800
Maximum finite-lived intangible asset, useful life (in years)			7 years

Goodwill and Intangible Asset49

Goodwill and Intangible Assets Goodwill Roll Forward (Details) $ in Thousands	9 Months Ended
	Sep. 24, 2016USD ($)
Goodwill [Roll Forward]
Balance as of December 26, 2015	$ 191,560
Foreign currency translation adjustments	(3,633)
Accumulated impairment loss	0
Balance as of September 24, 2016	$ 187,927

Goodwill and Intangible Asset50

Goodwill and Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 24, 2016	Dec. 26, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 150,380	$ 145,305
Accumulated Amortization	(28,754)	(9,507)
Net Carrying Amount	121,626	135,798
Intangible assets gross	162,693	165,826
Intangible assets	$ 133,939	$ 156,319
Weighted average remaining useful life (in years)	5 years	5 years 8 months 16 days
In-process technology
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 12,313	$ 20,521
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	234	239
Accumulated Amortization	(234)	(168)
Net Carrying Amount	$ 0	$ 71
Weighted average remaining useful life (in years)	0 days	2 months 12 days
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 49,042	$ 49,991
Accumulated Amortization	(6,753)	(2,197)
Net Carrying Amount	$ 42,289	$ 47,794
Weighted average remaining useful life (in years)	6 years 10 months 24 days	7 years 8 months 12 days
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 100,285	$ 94,256
Accumulated Amortization	(21,213)	(6,629)
Net Carrying Amount	$ 79,072	$ 87,627
Weighted average remaining useful life (in years)	4 years	4 years 7 months 24 days
Other intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 819	$ 819
Accumulated Amortization	(554)	(513)
Net Carrying Amount	$ 265	$ 306
Weighted average remaining useful life (in years)	4 years 10 months 24 days	5 years 7 months 13 days

Goodwill and Intangible Asset51

Goodwill and Intangible Assets Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Net Carrying Amount	$ 121,626	$ 135,798
Remainder of 2016	6,612
2,017	26,487
2,018	26,487
2,019	25,879
2,020	18,886
2021 and Thereafter	$ 17,275

Balance Sheet Details Selected

Balance Sheet Details Selected Balance Sheet Items (Details) - USD ($) $ in Thousands		Sep. 24, 2016	Dec. 26, 2015
Inventory:
Raw materials		$ 37,199	$ 27,879
Work in process		65,540	52,599
Finished goods		128,789	94,221
Total inventory		231,528	174,699
Property, plant and equipment, net:
Property, plant and equipment, gross		328,233	294,716
Less accumulated depreciation and amortization		(208,096)	(183,855)
Total property, plant and equipment, net		120,137	110,861
Accrued expenses:
Loss contingency related to non-cancelable purchase commitments		6,293	6,821
Professional and other consulting fees		4,198	5,363
Taxes payable		4,532	3,295
Royalties		5,376	4,290
Other accrued expenses		17,458	13,967
Total accrued expenses		37,857	33,736
Computer hardware
Property, plant and equipment, net:
Property, plant and equipment, gross		12,741	11,097
Computer software(1)
Property, plant and equipment, net:
Property, plant and equipment, gross	[1]	26,718	22,548
Laboratory and manufacturing equipment
Property, plant and equipment, net:
Property, plant and equipment, gross		215,690	189,168
Furniture and fixtures
Property, plant and equipment, net:
Property, plant and equipment, gross		2,060	1,897
Leasehold improvements
Property, plant and equipment, net:
Property, plant and equipment, gross		43,048	38,946
Construction in progress
Property, plant and equipment, net:
Property, plant and equipment, gross		27,976	31,060
Enterprise Resource Planning Systems
Property, plant and equipment, net:
Property, plant and equipment, gross		9,100	7,900
Total property, plant and equipment, net		$ 4,300	$ 4,000
[1]	Included in computer software at September 24, 2016 and December 26, 2015 were $9.1 million and $7.9 million, respectively, related to an ERP system that the Company implemented. The unamortized ERP costs at September 24, 2016 and December 26, 2015 were $4.3 million and $4.0 million, respectively

Accumulated Other Comprehensi53

Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ 1,123
Net current-period other comprehensive income (loss)	$ (4,273)	$ 4,819	(7,133)	$ 4,978
Ending balance	(6,010)		(6,010)
Unrealized gain (loss) on other available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(506)
Net current-period other comprehensive income (loss)			476
Ending balance	(30)		(30)
Foreign currency translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			2,389
Net current-period other comprehensive income (loss)			(7,609)
Ending balance	(5,220)		(5,220)
Accumulated tax effect
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(760)
Net current-period other comprehensive income (loss)			0
Ending balance	$ (760)		$ (760)

Basic and Diluted Net Income 54

Basic and Diluted Net Income (Loss) Per Common Share - Computation of Net Income (Loss) Per Common Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Numerator:
Net income (loss) attributable to Infinera Corporation	$ (11,172)	$ 8,510	$ 12,326	$ 38,782
Denominator:
Basic weighted average common shares outstanding (in shares)	143,850	134,834	142,350	131,007
Effect of dilutive securities:
Employee equity plans (in shares)	0	5,397	2,580	5,911
Assumed conversion of convertible senior notes from conversion spread (in shares)	0	5,069	991	4,164
Diluted weighted average common shares outstanding (in shares)	143,850	145,300	145,921	141,082
Net income (loss) per common share attributable to Infinera Corporation
Basic (in usd per share)	$ (0.08)	$ 0.06	$ 0.09	$ 0.30
Diluted (in usd per share)	$ (0.08)	$ 0.06	$ 0.08	$ 0.27

Basic and Diluted Net Income 55

Basic and Diluted Net Income (Loss) Per Common Share - Antidilutive Shares Excluded from Computation of Diluted Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	9,548	511	3,796	939
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	1,834	1	61	7
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	5,475	26	2,454	535
PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	905	0	643	97
ESPP shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	1,334	484	638	300

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details)	1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2013USD ($)d	Sep. 24, 2016USD ($)	Sep. 24, 2016USD ($)	Sep. 23, 2016$ / shares	Dec. 26, 2015USD ($)	Sep. 26, 2015	May 30, 2013USD ($)$ / shares
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase price as a percentage on principal amount of the notes upon the occurrence of a fundamental change	100.00%
Remaining life of note			20 months
Debt issuance costs, gross							$ 5,500,000
Deferred tax liability		$ 31,419,000	$ 31,419,000		$ 35,731,000
Total estimated fair value of the notes		156,000,000	156,000,000
Closing price of common stock (in usd per share) | $ / shares				$ 8.85
Other noncurrent assets | Accounting Standards Update 2015-03
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt issuance costs					(2,100,000)
Long-term debt | Accounting Standards Update 2015-03
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt issuance costs					2,100,000
1.75% Convertible Senior Notes Due June 1, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from issuance of debt, net			144,500,000
Initial conversion rate per $1,000 principal amount of Notes	0.0794834
Initial conversion price (in usd per share) | $ / shares							$ 12.58
Net equity component carrying amount		43,300,000	43,300,000		$ 43,300,000
Deferred tax liability		$ 17,000,000	$ 17,000,000
Debt instrument interest percentage		1.75%	1.75%				1.75%
Additional effective rate of interest to be used on amortized carrying value		10.23%	10.23%			10.23%
Convertible senior notes, conversion circumstance one
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold trading days for debt instrument conversion | d	20
Convertible threshold consecutive trading days	30 days	30 days
Convertible threshold minimum percentage	130.00%
Convertible senior notes, conversion circumstance two
Accounts, Notes, Loans and Financing Receivable [Line Items]
Convertible threshold consecutive trading days	5 days
Convertible threshold business days | d	5
Debt instrument, convertible, if-converted value in excess of principal	$ 1,000
Convertible, threshold maximum percentage	98.00%

Convertible Senior Notes - Comp

Convertible Senior Notes - Components of Convertible Senior Notes (Details) - USD ($)		Sep. 24, 2016	Dec. 26, 2015	May 30, 2013
Debt Instrument [Line Items]
Unamortized discount	[1]	$ (17,565,000)	$ (24,560,000)
Unamortized issuance cost	[1]	(1,511,000)	(2,113,000)
1.75% Convertible Senior Notes Due June 1, 2018
Debt Instrument [Line Items]
Principal amount				$ 150,000,000
Net carrying amount		130,924,000	123,327,000
1.75% Convertible Senior Notes Due June 1, 2018 | Long-term debt
Debt Instrument [Line Items]
Principal amount		$ 150,000,000	$ 150,000,000
[1]	Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately 20 months.

Convertible Senior Notes - Inte

Convertible Senior Notes - Interest Expense Recognized Related to Notes Prior to Capitalization of Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Debt Disclosure [Abstract]
Contractual interest expense	$ 656	$ 656	$ 1,969	$ 1,969
Amortization of debt issuance costs	206	186	602	544
Amortization of debt discount	2,391	2,162	6,996	6,328
Total interest expense	$ 3,253	$ 3,004	$ 9,567	$ 8,841

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 24, 2016USD ($)shares	Sep. 26, 2015USD ($)	Sep. 24, 2016USD ($)shares	Sep. 26, 2015USD ($)	Sep. 23, 2016$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock (in usd per share) | $ / shares					$ 8.85
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization of stock-based compensation	$ 7.7	$ 5.6	$ 21.4	$ 16.7
PSUs | Existing employees | Vesting 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Duration of grants based on shareholder return of common stock price versus designated index			1 year
PSUs | Existing employees | Vesting 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Duration of grants based on shareholder return of common stock price versus designated index			2 years
PSUs | Existing employees | Vesting 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Duration of grants based on shareholder return of common stock price versus designated index			3 years
Performance stock unit grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization of stock-based compensation	$ 1.7	$ 1.6	$ 4.9	$ 3.8
2016 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved Common stock for issuance of options (in shares) | shares	7.2		7.2
2016 Plan maximum term			10 years
Two Thousand And Seven Equity Incentive Plan | PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs			0
Two Thousand And Seven Equity Incentive Plan | PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs			2

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Company's Equity Award Activity - Options (Details) - Stock options $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 24, 2016USD ($)$ / sharesshares
Number of Stock Options
Number of options, beginning balance (in shares) | shares	2,511
Number of options, granted (in shares) | shares	0
Number of options, exercised (in shares) | shares	(651)
Number of options, canceled (in shares) | shares	(26)
Number of options, ending balance (in shares) | shares	1,834
Number of options, exercisable (in shares) | shares	1,826
Weighted-Average Exercise Price Per Share
Weighted-average exercise price per share, beginning balance (in usd per share) | $ / shares	$ 7.26
Weighted-average exercise per share, options granted (in usd per share) | $ / shares	0
Weighted-average exercise price per share, options exercised (in usd per share) | $ / shares	4.42
Weighted-average exercise price per share, options canceled (in usd per share) | $ / shares	12.38
Weighted-average exercise price per share, ending balance (in usd per share) | $ / shares	8.19
Average exercise price per dhare, exercisable (in usd per share) | $ / shares	$ 8.19
Aggregate Intrinsic Value
Aggregate intrinsic value, beginning balance | $	$ 28,288
Aggregate intrinsic value, options exercised | $	4,158
Aggregate intrinsic value, ending balance | $	1,761
Aggregate intrinsic value, exercisable | $	$ 1,761

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Company's Equity Award Activity - RSUs (Details) - Restricted stock units $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 24, 2016USD ($)$ / sharesshares
Number of Restricted Stock Units
Number of units, beginning balance (in shares) | shares	4,932
Number of shares available for grant cost (in shares) | shares	2,791
Number of restricted/performance stock units, released (in shares) | shares	(1,984)
Number of restricted stock units, canceled (in shares) | shares	(263)
Number of units, ending balance (in shares) | shares	5,476
Weighted- Average Grant Date Fair Value Per Share
Weighted-average grant date fair value per share, beginning balance (in usd per share) | $ / shares	$ 12.76
Weighted-average fair value, granted (in usd per share) | $ / shares	14.32
Weighted-average grant date fair value per share, released (in usd per share) | $ / shares	10.63
Weighted-average grant date fair value per share, canceled (in usd per share) | $ / shares	13.74
Weighted-average grant date fair value per share, ending balance (in usd per share) | $ / shares	$ 14.28
Aggregate Intrinsic Value
Aggregate intrinsic value, beginning balance | $	$ 91,285
Aggregate intrinsic value, RSUs released | $	23,948
Aggregate intrinsic value, ending balance | $	$ 48,461

Stockholders' Equity - Summar62

Stockholders' Equity - Summary of Company's Equity Award Activity - PSUs (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 24, 2016USD ($)$ / sharesshares
PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	731
Number of shares available for grant cost (in shares)	647
Number of restricted/performance stock units, released (in shares)	(615)
Number of restricted stock units, canceled (in shares)	(92)
Number of units, ending balance (in shares)	905
Number of restricted stock units, expected to vest (in shares)	195
Weighted- Average Grant Date Fair Value Per Share
Weighted-average grant date fair value per share, beginning balance (in usd per share) | $ / shares	$ 12.35
Weighted-average fair value, granted (in usd per share) | $ / shares	15.28
Weighted-average grant date fair value per share, released (in usd per share) | $ / shares	11.25
Weighted-average grant date fair value per share, canceled (in usd per share) | $ / shares	15.21
Weighted-average grant date fair value per share, ending balance (in usd per share) | $ / shares	$ 14.02
Aggregate Intrinsic Value
Aggregate intrinsic value, beginning balance | $	$ 13,540
Aggregate Intrinsic Value, PSUs released | $	8,077
Aggregate intrinsic value, ending balance | $	8,008
Aggregate intrinsic value, expected to vest | $	$ 1,725
Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	234	[1],[2]
Weighted- Average Grant Date Fair Value Per Share
Weighted-average fair value, granted (in usd per share) | $ / shares	$ 12.28	[1]
[1]	Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.
[2]	Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.

Stockholders' Equity - Total St

Stockholders' Equity - Total Stock Based Compensation Cost for Instruments Granted but Not Yet Amortized (Details) $ in Thousands	9 Months Ended
	Sep. 24, 2016USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, unrecognized compensation expense, net	$ 30
Stock options, weighted-average period (in years)	1 year 3 months 18 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, net	$ 60,952
Weighted-average period (in years)	2 years 7 months 6 days
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, net	$ 7,163
Weighted-average period (in years)	1 year 7 months 6 days

Stockholders' Equity - Estimate

Stockholders' Equity - Estimated Fair Value of ESPP, Valuation Assumptions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 10,211	$ 8,451	$ 29,191	$ 23,868
Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility	67.00%	39.00%
Risk-free interest rate	0.51%	0.26%
Expected life	6 months	6 months	6 months	6 months
Estimated fair value (in usd per share)	$ 3.16	$ 6.43
Stock-based compensation expense	$ 1,565	$ 1,147	$ 4,054	$ 3,275
Minimum | Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility			56.00%	39.00%
Risk-free interest rate			0.51%	0.13%
Estimated fair value (in usd per share)			$ 3.16	$ 5.15
Maximum | Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility			67.00%	53.00%
Risk-free interest rate			0.52%	0.26%
Estimated fair value (in usd per share)			$ 4.53	$ 6.43

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity - Schedule of Share-based Payment Award, Valuation Assumptions (Details) - PSUs	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 24, 2016	Sep. 24, 2016$ / shares	Dec. 26, 2015$ / shares	Dec. 27, 2014$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SPGIIPTR Index Expected Volatility Rate	18.00%			25.00%
Volatility	55.00%		48.00%
Correlation With SPGIIPTR Index			0.52	0.60
Estimated Fair Value (in usd per share)		$ 15.28
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SPGIIPTR Index Expected Volatility Rate			18.00%
Volatility				49.00%
Risk-free interest rate		0.95%	0.97%	0.66%
Correlation With SPGIIPTR Index		0.58
Estimated Fair Value (in usd per share)		$ 10.31	$ 18.08	$ 6.59
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SPGIIPTR Index Expected Volatility Rate			19.00%
Volatility				50.00%
Risk-free interest rate		1.07%	1.10%	0.71%
Correlation With SPGIIPTR Index		0.59
Estimated Fair Value (in usd per share)		$ 16.62	$ 19.29	$ 7.60

Stockholders' Equity Stockhol66

Stockholders' Equity Stockholders' Equity - Schedule Of Nonvested Performance Based Units Activity By Grant Year (Details) shares in Thousands	9 Months Ended
	Sep. 24, 2016shares
PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	731
Number of shares available for grant cost (in shares)	647
Number of restricted/performance stock units, released (in shares)	(615)
Number of restricted stock units, canceled (in shares)	(92)
Number of units, ending balance (in shares)	905
Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	234	[1],[2]
2013 | PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	147
Number of shares available for grant cost (in shares)	0
Number of restricted/performance stock units, released (in shares)	(211)
Number of restricted stock units, canceled (in shares)	(6)
Number of units, ending balance (in shares)	0
2013 | Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	70	[2]
2014 | PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	260
Number of shares available for grant cost (in shares)	0
Number of restricted/performance stock units, released (in shares)	(179)
Number of restricted stock units, canceled (in shares)	(11)
Number of units, ending balance (in shares)	123
2014 | Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	53	[2]
2015 | PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	324
Number of shares available for grant cost (in shares)	0
Number of restricted/performance stock units, released (in shares)	(225)
Number of restricted stock units, canceled (in shares)	(62)
Number of units, ending balance (in shares)	148
2015 | Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	111	[2]
2016 | PSUs
Number of Performance Stock Units
Number of units, beginning balance (in shares)	0
Number of shares available for grant cost (in shares)	647
Number of restricted/performance stock units, released (in shares)	0
Number of restricted stock units, canceled (in shares)	(13)
Number of units, ending balance (in shares)	634
2016 | Additional grants for performance
Number of Performance Stock Units
Number of shares available for grant cost (in shares)	0	[2]
[1]	Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.
[2]	Represents the additional PSUs awarded resulting from the achievement of performance goals above the performance targets established at grant since the original grants were at 100% of target amounts.

Stockholders' Equity - Summar67

Stockholders' Equity - Summary of Effects of Stock-Based Compensation on Company's Balance Sheet and Statements of Operations (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015	Dec. 26, 2015
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes		$ 9,543	$ 7,475	$ 26,752	$ 21,251
Cost of revenue - amortization from balance sheet	[1]	668	976	2,439	2,617
Stock-based compensation expense		10,211	8,451	29,191	23,868
Cost of revenue
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes		756	645	2,175	1,740
Research and development
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes		3,496	2,788	9,721	8,183
Sales and marketing
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes		2,826	2,131	8,006	5,922
General and administration
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes		2,465	$ 1,911	6,850	$ 5,406
Stock-based compensation effects in inventory
Effects Of Stock Based Compensation [Line Items]
Effects Of Stock Based Compensation		4,378		4,378		$ 3,129
Stock-based compensation effects in property, plant and equipment, net
Effects Of Stock Based Compensation [Line Items]
Effects Of Stock Based Compensation		$ 74		$ 74		$ 93
[1]	Stock-based compensation expense deferred to inventory and deferred inventory costs in prior periods and recognized in the current period.

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Business Acquisition [Line Items]
Provision (benefit) for income taxes	$ (2,416)	$ (151)	$ (725)	$ 1,473
Pre-tax income (loss)	(13,713)	$ 8,359	11,098	$ 40,255
Income tax benefit increase (decrease)	2,000		1,200
Transmode
Business Acquisition [Line Items]
Provision (benefit) for income taxes	(1,500)		(4,600)
Purchase accounting amortization expense	$ 6,900		$ 21,000

Segment Information - Revenue

Segment Information - Revenue and Long-Lived Assets by Geographic Region (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016USD ($)	Sep. 26, 2015USD ($)	Sep. 24, 2016USD ($)segment	Sep. 26, 2015USD ($)
Segment Reporting [Abstract]
Number of reporting segments | segment			1
Number of operating segments | segment			1
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 185,452	$ 232,472	$ 689,092	$ 626,680
Operating segments | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	104,045	158,845	445,270	440,610
Operating segments | Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	17,390	20,874	31,916	39,944
Operating segments | Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	121,435	179,719	477,186	480,554
Operating segments | Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	51,940	41,655	176,386	114,163
Operating segments | Asia Pacific and Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 12,077	$ 11,098	$ 35,520	$ 31,963

Segment Information - Property,

Segment Information - Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	$ 120,137	$ 110,861
Operating segments | United States
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	112,439	102,702
Operating segments | Other Americas
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	247	173
Operating segments | Americas
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	112,686	102,875
Operating segments | Europe, Middle East and Africa
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	4,447	5,417
Operating segments | Asia Pacific and Japan
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	$ 3,004	$ 2,569

Guarantees - Additional Informa

Guarantees - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 24, 2016	Dec. 26, 2015
Guarantor Obligations [Line Items]
Software warranty period	90 days
Outstanding standby letters of credit	$ 10.1	$ 5.2
Debt instrument, collateral amount	4.8	4.8
Banker's guarantees or performance bonds
Guarantor Obligations [Line Items]
Line of credit facility, maximum borrowing capacity	1.3	1.5
Proceeds from lines of credit	0.7	0.7
Letter of credit
Guarantor Obligations [Line Items]
Customer proposal guarantee	4.4	3.1
Value added tax license	1.2	1.2
Property leases	$ 4.5	$ 0.9
Minimum
Guarantor Obligations [Line Items]
Product warranty period	1 year
Maximum
Guarantor Obligations [Line Items]
Product warranty period	5 years

Guarantees - Activity Related t

Guarantees - Activity Related to Product Warranty (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance		$ 40,989	$ 28,439	$ 38,844	$ 27,040
Charges to operations		5,196	10,791	19,258	22,158
Utilization		(5,002)	(3,515)	(13,691)	(8,336)
Change in estimate	[1]	(2,562)	1,026	(5,790)	(4,121)
Balance at the end of the period		$ 38,621	$ 36,741	$ 38,621	$ 36,741
[1]	The Company records hardware warranty liabilities based on the latest quality and cost information available as of that date. The changes in estimate shown here are due to changes in overall actual failure rates, the mix of new versus used units related to replacement of failed units, and changes in the estimated cost of repair. As the Company's products mature over time, failure rates and repair costs generally decline leading to favorable changes in warranty reserves.