Infinera (INFN) 10-Q 4 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 28, 2015	Apr. 28, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	28-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	INFN
Entity Registrant Name	INFINERA CORP
Entity Central Index Key	1138639
Current Fiscal Year End Date	-14
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		129,624,376

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$118,623	$86,495
Short-term investments	215,080	239,628
Accounts receivable, net of allowance for doubtful accounts of $20 in 2015 and $38 in 2014	131,224	154,596
Inventory	157,195	146,500
Prepaid expenses and other current assets	23,112	24,636
Total current assets	645,234	651,855
Property, plant and equipment, net	82,661	81,566
Long-term investments	69,835	59,233
Cost-method investment	14,500	14,500
Long-term restricted cash	5,108	5,460
Other non-current assets	5,692	5,402
Total assets	823,030	818,016
Current liabilities:
Accounts payable	50,183	61,533
Accrued expenses	28,061	26,441
Accrued compensation and related benefits	24,406	38,795
Accrued warranty	11,453	12,241
Deferred revenue	36,757	35,321
Total current liabilities	150,860	174,331
Long-term debt, net	118,951	116,894
Accrued warranty, non-current	14,086	14,799
Deferred revenue, non-current	12,119	10,758
Other long-term liabilities	19,179	19,327
Commitments and contingencies (Note 14)
Stockholders’ equity:
Preferred stock, $0.001 par value Authorized shares – 25,000 and no shares issued and outstanding	0	0
Issued and outstanding shares – 129,094 as of March 28, 2015 and 126,160 as of December 27, 2014	129	126
Additional paid-in capital	1,090,676	1,077,225
Accumulated other comprehensive loss	-4,510	-4,618
Accumulated deficit	-578,460	-590,826
Total stockholders’ equity	507,835	481,907
Total liabilities and stockholders’ equity	$823,030	$818,016

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Net of allowance for doubtful accounts	$20	$38
Preferred stock, par value (in usd per share)	$0.00	$0.00
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)	$0.00	$0.00
Common stock, authorized shares (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	129,093,644	126,160,000
Common stock, shares outstanding (in shares)	129,093,644	126,160,000

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Revenue:
Product	$160,843	$124,242
Services	26,019	18,573
Total revenue	186,862	142,815
Cost of revenue:
Cost of product	89,506	78,438
Cost of services	9,244	5,971
Total cost of revenue	98,750	84,409
Gross profit	88,112	58,406
Operating expenses:
Research and development	39,257	29,346
Sales and marketing	21,042	17,862
General and administrative	12,656	12,254
Total operating expenses	72,955	59,462
Income (loss) from operations	15,157	-1,056
Other income (expense), net:
Interest income	414	336
Interest expense	-2,890	-2,677
Other gain (loss), net	301	-729
Total other income (expense), net	-2,175	-3,070
Income (loss) before income taxes	12,982	-4,126
Provision for income taxes	616	248
Net income (loss)	$12,366	($4,374)
Net income (loss) per common share:
Basic (in usd per share)	$0.10	($0.04)
Diluted (in usd per share)	$0.09	($0.04)
Weighted average shares used in computing net income (loss) per common share:
Basic weighted average common shares outstanding (in shares)	127,840	121,352
Diluted weighted average common shares outstanding (in shares)	137,304	121,352

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$12,366	($4,374)
Other comprehensive income (loss):
Unrealized gain on all other available-for-sale investments	267	50
Foreign currency translation adjustment	-159	244
Tax related to available-for-sale investment	0	-20
Net change in accumulated other comprehensive income	108	274
Comprehensive income (loss)	$12,474	($4,100)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Cash Flows from Operating Activities:
Net income (loss)	$12,366	($4,374)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	6,586	6,314
Amortization of debt discount and issuance costs	2,234	2,020
Amortization of premium on investments	954	828
Stock-based compensation expense	7,208	6,672
Other gain	-19	-20
Changes in assets and liabilities:
Accounts receivable	23,391	-6,762
Inventory	-12,103	-3,354
Prepaid expenses and other assets	1,141	-3,797
Accounts payable	-10,317	-2,080
Accrued liabilities and other expenses	-12,895	-13,448
Deferred revenue	2,797	-909
Accrued warranty	-1,501	3,477
Net cash provided by (used in) operating activities	19,842	-15,433
Cash Flows from Investing Activities:
Purchase of available-for-sale investments	-80,022	-80,223
Proceeds from sale of available-for-sale investments	2,001	0
Proceeds from maturities of investments	91,280	57,063
Purchase of property and equipment	-7,367	-5,608
Change in restricted cash	352	-479
Net cash provided by (used in) investing activities	6,244	-29,247
Cash Flows from Financing Activities:
Proceeds from issuance of common stock	10,131	7,054
Minimum tax withholding paid on behalf of employees for net share settlement	-3,950	-1,619
Net cash provided by financing activities	6,181	5,435
Effect of exchange rate changes on cash	-139	164
Net change in cash and cash equivalents	32,128	-39,081
Cash and cash equivalents at beginning of period	86,495	124,330
Cash and cash equivalents at end of period	118,623	85,249
Supplemental disclosures of cash flow information:
Cash paid for income taxes, net of refunds	897	303
Supplemental schedule of non-cash financing activities:
Transfer of inventory to fixed assets	$1,403	$603

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 28, 2015
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies
	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 27, 2014.
	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, 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 property, plant and equipment, fair value measurement of the liability component of the convertible senior notes, other-than-temporary impairments and derivative instruments. 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 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 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 27, 2014.
	There have been no material changes in the Company’s significant accounting policies for the three months ended March 28, 2015 as compared to those disclosed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 27, 2014.
	To date, a few of the Company’s customers have accounted for a significant portion of its revenue.  For the three months ended March 28, 2015, two customers individually accounted for 18% and 16% of the Company’s total revenue, respectively. For the three months ended March 29, 2014, two customers individually accounted for 21% and 16% of the Company’s total revenue, respectively.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 28, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In February 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update 2015-02, "Consolidation (Topic 10): Amendments to the Consolidation Analysis" (“ASU 2015-02”). ASU 2015-02 provides guidance on the consolidation evaluation for reporting organizations that are required to evaluate whether they should consolidate certain legal entities. In accordance with ASU 2015-02, all legal entities are subject to reevaluation under the revised consolidation model. ASU 2015-02 will be effective for the Company in its first quarter of fiscal 2016. The Company is currently evaluating the impact of the pending adoption of ASU 2015-02 on its consolidated financial statements.
	In January 2015, the FASB issued Accounting Standards Update 2015-01, "Income Statement - Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items" (“ASU 2015-01”). ASU 2015-01 eliminates the concept of an extraordinary item from GAAP. As a result, an entity will no longer be required to segregate extraordinary items from the results of ordinary operations, to separately present an extraordinary item on its income statement, net of tax, after income from continuing operations or to disclose income taxes and earnings-per-share data applicable to an extraordinary item. However, ASU 2015-01 will still retain the presentation and disclosure guidance for items that are unusual in nature and occur infrequently. ASU 2015-01 will be effective for the Company in its first quarter of fiscal 2017. The adoption of ASU 2015-01 is not expected to have a material effect on the Company’s consolidated financial statements.
	In June 2014, the FASB issued Accounting Standards Update No. 2014-12, "Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period" ("ASU 2014-12"). ASU 2014-12 requires that a performance target that affects vesting and could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance in Accounting Standard Codification ("ASC") 718, "Compensation—Stock Compensation" ("ASC 718"), as it relates to such awards. ASU 2014-12 will be effective for the Company's first quarter of fiscal 2017 with early adoption permitted using either of two methods: (i) prospective to all awards granted or modified after the effective date; or (ii) retrospective to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter, with the cumulative effect of applying ASU 2014-12 as an adjustment to the opening retained earnings balance as of the beginning of the earliest annual period presented in the financial statements. The Company is currently evaluating the impact of the pending adoption of ASU 2014-12 on the Company's consolidated financial statements.
	In May 2014, the Financial Accounting Standards Board (FASB") issued Accounting Standards Update 2014-09, "Revenue from Contracts from Customers" ("ASU 2014-09"). ASU 2014-09 provides a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. ASU 2014-09 will require an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update creates a five-step model that requires entities to exercise judgment when considering the terms of the contract(s), which include (i) identifying the contract(s) with the customer; (ii) identifying the separate performance obligations in the contract; (iii) determining the transaction price; (iv) allocating the transaction price to the separate performance obligations; and (v) recognizing revenue when each performance obligation is satisfied. ASU 2014-09 will be effective for the Company’s first quarter of 2017. The Company has the option to apply the provisions of ASU 2014-09 either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of applying this ASU recognized at the date of initial application. Early adoption is not permitted. The Company is currently evaluating the method and impact the adoption of ASU 2014-09 will have on the Company's consolidated financial statements.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 28, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	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 debt securities at fair value and classifies its securities 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, 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.
	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.
	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.
	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 March 28, 2015												As of December 27, 2014
		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	$	39,633		$	—		$	—		$	39,633		$	21,478	$	—		$	—	$	21,478
	Certificates of deposit	—			9,465			—			9,465			—		8,060			—		8,060
	Commercial paper	—			21,690			—			21,690			—		46,072			—		46,072
	Corporate bonds	—			223,238			—			223,238			—		235,285			—		235,285
	U.S. agency notes	—			14,508			—			14,508			—		—			—		—
	U.S. treasuries	16,014			—			—			16,014			14,810		—			—		14,810
	Foreign currency exchange forward contracts	—			—			—			—			—		—			—		—
	Total assets	$	55,647		$	268,901		$	—		$	324,548		$	36,288	$	289,417		$	—	$	325,705
	Liabilities
	Foreign currency exchange forward contracts	$	—		$	(117	)	$	—		$	(117	)	$	—	$	(64	)	$	—	$	(64	)
	During the three months ended March 28, 2015, there were no transfers of assets or liabilities between Level 1 and Level 2.
	Investments at fair value were as follows (in thousands):
		28-Mar-15
		Adjusted Amortized Cost			Gross Unrealized Gains			Gross Unrealized			Fair Value
								Losses
	Money market funds	$	39,633		$	—		$	—		$	39,633
	Certificates of deposit	9,460			5			—			9,465
	Commercial paper	21,691			—			(1		)	21,690
	Corporate bonds	223,425			12			(199		)	223,238
	U.S. agency notes	14,507			5			(4		)	14,508
	U.S. treasuries	16,009			9			(4		)	16,014
	Total available-for-sale investments	$	324,725		$	31		$	(208	)	$	324,548
		December 27, 2014
		Adjusted Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	Money market funds	$	21,478		$	—		$	—		$	21,478
	Certificates of deposit	8,060			—			—			8,060
	Commercial paper	46,073			—			(1		)	46,072
	Corporate bonds	235,713			2			(430		)	235,285
	U.S. treasuries	14,825			1			(16		)	14,810
	Total available-for-sale investments	$	326,149		$	3		$	(447	)	$	325,705
	As of March 28, 2015, the Company’s available-for-sale investments in certificates of deposit, commercial paper, corporate bonds, U.S. agency notes and U.S. treasuries have a contractual maturity term of up to 24 months. Gross realized gains (losses) on short-term and long-term investments for the three months ended March 28, 2015 and March 29, 2014 were insignificant in both periods. The specific identification method is used to account for gains and losses on available-for-sale investments.
	As of March 28, 2015 and December 27, 2014, the Company held $79.0 million and $59.7 million of cash in banks, respectively, excluding restricted cash.

Costmethod_Investment

Cost-method Investment	3 Months Ended
	Mar. 28, 2015
Investments, All Other Investments [Abstract]
Cost-method Investment	Cost-method Investment
	As of March 28, 2015, the Company had an investment of $14.5 million in a privately-held company. This investment is accounted for as a cost-method investment, 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 the entity. This investment is carried at historical cost in the Company's condensed consolidated financial statements. The Company regularly evaluates the carrying value of this cost-method investment for impairment. If the Company believes that the carrying value of the cost basis investment 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 March 28, 2015, no event had occurred that would adversely affect the carrying value of this investment and thus no impairment charges have been recorded for this cost-method investment.

Derivative_Instruments

Derivative Instruments	3 Months Ended
	Mar. 28, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments
	Foreign Currency Exchange Forward Contracts
	The Company enters into foreign currency exchange forward contracts to manage its exposure to fluctuations in foreign exchange rates that arise primarily from its euro and British pound denominated receivables and euro denominated restricted cash balance amounts that are pledged as collateral for certain stand-by and commercial letters of credit. 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. The forward contracts are with one high-quality institution and the Company consistently monitors the creditworthiness of the counterparty. The forward contracts entered into during the three months ended March 28, 2015 were denominated in euros and British pounds, and had maturities of no more than 35 days. The contracts are settled for U.S. dollars at maturity at rates agreed to at inception of the contracts.
	As of March 28, 2015, the Company did not designate foreign currency exchange forward contracts as hedges for accounting purposes, and accordingly changes in the fair value of these instruments are included in other gain (loss), net, in the accompanying condensed consolidated statements of operations. For the three months ended March 28, 2015 and March 29, 2014, the before-tax effect of foreign currency exchange forward contracts was a gain of $3.3 million and a loss of $1.2 million, respectively. In each of these periods, the impact of these gross gains and losses were offset by foreign exchange rate fluctuations on the underlying foreign currency denominated amounts and the combined effect is recorded in other gain (loss), net, in the accompanying condensed consolidated statements of operations.
	The fair value of derivative instruments in the Company’s condensed consolidated balance sheets was as follows (in thousands):
		As of March 28, 2015					As of December 27, 2014
		Gross Notional(1)		Other			Gross Notional(1)		Other
				Accrued					Accrued
				Liabilities					Liabilities
	Foreign currency exchange forward contracts
	Related to euro denominated receivables	$	22,350	$	(107	)	$	34,445	$	(53	)
	Related to British pound denominated receivables	1,590		(5		)	2,678		(9		)
	Related to restricted cash	1,103		(5		)	1,236		(2		)
		$	25,043	$	(117	)	$	38,359	$	(64	)
	(1)	Represents the face amounts of forward contracts that were outstanding as of the period noted.

Balance_Sheet_Details

Balance Sheet Details	3 Months Ended
	Mar. 28, 2015
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):
		28-Mar-15			27-Dec-14
	Inventory:
	Raw materials	$	22,372		$	15,169
	Work in process	45,871			50,046
	Finished goods (1)	88,952			81,285
	Total inventory	$	157,195		$	146,500
	Property, plant and equipment, net:
	Computer hardware	$	9,584		$	8,785
	Computer software(2)	18,705			17,684
	Laboratory and manufacturing equipment	166,514			162,004
	Furniture and fixtures	1,433			1,340
	Leasehold improvements	38,450			37,825
	Construction in progress	15,340			14,726
	Subtotal	$	250,026		$	242,364
	Less accumulated depreciation and amortization	(167,365		)	(160,798		)
	Total property, plant and equipment, net	$	82,661		$	81,566
	Accrued expenses:
	Loss contingency related to non-cancelable purchase commitments	$	5,048		$	5,390
	Professional and other consulting fees	2,631			1,831
	Taxes payable	2,853			3,993
	Royalties	3,009			2,648
	Accrued rebate and customer prepay liability	1,026			941
	Accrued interest on convertible senior notes	875			219
	Other accrued expenses	12,619			11,419
	Total accrued expenses	$	28,061		$	26,441
	(1)	Included in finished goods inventory at March 28, 2015 and December 27, 2014 were $12.9 million and $10.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
	(2)	Included in computer software at March 28, 2015 and December 27, 2014 were $7.9 million and $7.9 million, respectively, related to an enterprise resource planning ("ERP") system that the Company implemented during 2012. The unamortized ERP costs at March 28, 2015 and December 27, 2014 were $4.9 million and $5.2 million, respectively.
	Restricted Cash
	The Company’s long-term restricted cash balance is primarily comprised of certificates of deposit, of which the majority is not insured by the Federal Deposit Insurance Corporation. These amounts primarily collateralize the Company’s issuances of stand-by and commercial letters of credit. Additionally, the Company’s restricted cash balance includes a leave encashment fund for India employees and a corporate bank card deposit for employees in the United Kingdom.
	The following table sets forth the Company's restricted cash (in thousands):
		28-Mar-15			27-Dec-14
	Restricted cash related to outstanding standby letters of credit
	Value added tax license	$	1,177		$	1,309
	Customer proposal guarantee	2,832			3,074
	Property leases	699			699
	Other	400			378
	Total restricted cash	$	5,108		$	5,460

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 28, 2015
Equity [Abstract]
Accumulated Other Comprehensive Loss	Comprehensive Loss
	Other comprehensive loss includes certain changes in equity that are excluded from net income (loss). The following table sets forth the changes in accumulated other comprehensive loss by component for the three months ended March 28, 2015 (in thousands):
		Unrealized Gain			Foreign			Accumulated			Total
		on Other			Currency Translation			Tax Effect
		Available-for-Sale
		Securities
	Balance at December 27, 2014	$	(444	)	$	(3,414	)	$	(760	)	$	(4,618	)
	Net current-period other comprehensive loss	267			(159		)	—			108
	Balance at March 28, 2015	$	(177	)	$	(3,573	)	$	(760	)	$	(4,510	)

Basic_and_Diluted_Net_Income_L

Basic and Diluted Net Income (Loss) Per Common Share	3 Months Ended
	Mar. 28, 2015
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) by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per common share is computed using net income (loss) 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"), assumed conversion of the Notes from conversion spread (as defined in Note 9, "Convertible Senior Notes"), and assumed issuance of stock under the Company’s employee stock purchase plan ("ESPP") using the treasury stock method. 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 anti-dilutive and therefore, 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
		28-Mar-15			29-Mar-14
	Numerator:
	Net income (loss)	$	12,366		$	(4,374	)
	Denominator:
	Basic weighted average common shares outstanding	127,840			121,352
	Effect of dilutive securities:
	Employee equity plans	6,569			—
	Assumed conversion of convertible senior notes from conversion spread	2,895			—
	Diluted weighted average common shares outstanding	137,304			121,352
	Net income (loss) per common share
	Basic	$	0.1		$	(0.04	)
	Diluted	$	0.09		$	(0.04	)
	In the three months ended March 28, 2015, the Company included the dilutive effects of the Company's Notes in the calculation of diluted net income per common shares as the average market price was above the conversion price. The dilutive impact of the Company's Notes was based on the difference between the Company's average stock price during the quarter and the conversion price of the Notes. In the three months ended March 29, 2014, the Company excluded the potential shares issuable upon conversion of the Notes in the calculation of diluted earnings per share because the market price was below the conversion price. 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 unless their effect is anti-dilutive.
	The effects of potentially outstanding shares were not included in the calculation of diluted net income per share for the three months ended March 28, 2015 because their effect would have been anti-dilutive under the treasury stock method or the performance condition of the award has not been met. As the Company incurred a net loss during the three months ended March 29, 2014, all potential stock options, RSUs, PSUs and ESPP shares have been excluded from the diluted net loss per share computation as their effects were deemed anti-dilutive.
	The following sets forth the potentially dilutive shares excluded from the computation of the diluted net income (loss) per share because their effect would have been anti-dilutive (in thousands):
		Three Months Ended
		28-Mar-15		29-Mar-14
	Stock options	10		6,135
	Restricted stock units	1,505		5,386
	Performance stock units	292		763
	Employee stock purchase plan shares	415		431
	Total	2,222		12,715

Convertible_Senior_Notes

Convertible Senior Notes	3 Months Ended
	Mar. 28, 2015
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes
	In May 2013, the Company issued $150.0 million of 1.75% convertible senior notes due June 1, 2018 (the “Notes”). The Notes 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 as cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, for any remaining conversion obligation. 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 September 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):
		28-Mar-15			December 27, 2014
	Principal	$	150,000		$	150,000
	Unamortized discount (1)	(31,049		)	(33,106		)
	Unamortized issuance cost (1)	(2,671		)	(2,848		)
	Net carrying amount	116,280			114,046
	(1)	Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately three years.
	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. As of March 28, 2015 and December 27, 2014, the carrying amount of the equity component was $43.3 million, which represents the equity component of the debt discount related to the value of the conversion option of $45.0 million, net of the debt issuance costs attributable to the equity component of $1.7 million. 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 recorded as other non-current assets and will be amortized to interest expense over the term of the Notes. 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
		28-Mar-15			29-Mar-14
	Contractual interest expense	$	656		$	657
	Amortization of debt issuance costs	177			160
	Amortization of debt discount	2,057			1,860
	Total interest expense	$	2,890		$	2,677
	The coupon rate was 1.75%. For the three months ended March 28, 2015 and March 29, 2014, 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 March 28, 2015, the fair value of the Notes was $245.4 million. The fair value was determined based on the quoted bid price of the Notes in an over-the-counter market on March 27, 2015. The Notes are classified as Level 2 of the fair value hierarchy.
	During the three months ended March 28, 2015, the closing price of the Company's common stock exceeded 130% of the applicable conversion price of the Notes on at least 20 of the last 30 consecutive trading days of the quarter; therefore, holders of the Notes may convert their notes during the three months ended June 27, 2015. Should the closing price conditions be met during the 30 consecutive trading days prior to the end of the second quarter of 2015 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 $19.59 on March 27, 2015, the if-converted value of the Notes exceeded their principal amount by approximately $83.6 million.

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 28, 2015
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 employee stock purchase plan ("ESPP") for all eligible employees. As of March 28, 2015, there were a total of 15.7 million shares of common stock available for grant under the Company’s 2007 Equity Incentive Plan ("2007 Plan"). The following tables summarize the Company’s equity award activity and related information (in thousands, except per share data):
		Number of Stock			Weighted-Average			Aggregate
		Options			Exercise			Intrinsic
					Price			Value
					Per Share
	Outstanding at December 27, 2014	4,298			$	7.29		$	32,833
	Stock options granted	—			$	—
	Stock options exercised	(559	)		$	6.74		$	5,789
	Stock options canceled	—			$	—
	Outstanding at March 28, 2015	3,739			$	7.37		$	45,711
	Vested and expected to vest as of March 28, 2015	3,737						$	45,690
	Exercisable at March 28, 2015	3,687			$	7.36		$	45,097
	The aggregate intrinsic value of unexercised stock options is calculated as the difference between the closing price of the Company’s common stock of $19.59 at March 27, 2015 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.
		Number of			Weighted-			Aggregate
		Restricted			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 27, 2014	6,042			$	8.14		$	90,085
	RSUs granted	1,581			$	17.95
	RSUs released	(1,393	)		$	7.97		$	22,807
	RSUs canceled	(78	)		$	8.58
	Outstanding at March 28, 2015	6,152			$	10.69		$	120,514
	Expected to vest at March 28, 2015	5,798						$	113,574
		Number of			Weighted-			Aggregate
		Performance			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 27, 2014	876			$	7.49		$	13,067
	PSUs granted	438			$	14.97
	PSUs released	(386	)		$	6.67		$	6,585
	PSUs canceled	(191	)		$	7.88
	Outstanding at March 28, 2015	737			$	12.14		$	14,444
	Expected to vest at March 28, 2015	703						$	13,764
	The aggregate intrinsic value of unreleased RSUs and unreleased PSUs is calculated using the closing price of the Company's common stock of $19.59 at March 27, 2015. 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 March 28, 2015. 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			Weighted-
		Compensation			Average Period
		Expense, Net			(in years)
	Stock options	170			1.5
	RSUs	48,111			2.7
	PSUs	7,083			1.6
	Employee Stock Options
	The estimated values of stock options, as well as assumptions used in calculating these values were based on estimates as follows (expense amounts in thousands):
		Three Months Ended
	Employee and Director Stock Options	28-Mar-15		29-Mar-14
	Volatility	N/A		52%
	Risk-free interest rate	N/A		1.30%
	Expected life	N/A		4.3 years
	Estimated fair value	N/A		$3.85
	Total stock-based compensation expense	$70		$388
	_________________
	N/A	Not applicable because the Company did not grant any stock options during the period.
	Employee Stock Purchase Plan
	The fair value of the ESPP shares was estimated at the date of grant using the following assumptions (expense amounts in thousands):
		Three Months Ended
	Employee Stock Purchase Plan	28-Mar-15		29-Mar-14
	Volatility	53%		51%
	Risk-free interest rate	0.13%		0.11%
	Expected life	0.5 years		0.5 years
	Estimated fair value	$5.15		$2.57
Total stock-based compensation expense	$1,051		$791
Restricted Stock Units
During the three months ended March 28, 2015, the Company granted RSUs to employees and members of the Company’s board of directors to receive an aggregate of 1.6 million shares of the Company’s common stock. 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 months ended March 28, 2015 and March 29, 2014 was approximately $5.2 million and $5.1 million, respectively.
Performance Stock Units
2015 Performance Stock Units
Pursuant to the 2007 Plan, during the first quarter of 2015, the Company granted 0.2 million target number of PSUs to certain of the Company's executive officers. The number of shares to be issued upon vesting of PSUs range from 0 to 1.5 times the target number PSUs granted depending on the relative performance of the Company's common stock price compared to the S&P North American Technology Multimedia Networking ("SPGIIPTR") Index over the span of one, two and three years of total shareholder returns.
The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
		Three Months Ended
		28-Mar-15
Infinera Volatility		48%
SPGIIPTR Index Volatility		18% - 19%
Risk-free interest rate		0.97% - 1.10%
Correlation with SPGIIPTR Index		0.52
Estimated fair value		$18.08 - $19.29
Additionally, pursuant to the 2007 Plan, during the three months ended March 28, 2015, the Company granted 0.1 million target number of PSUs to certain of its executive officers. These PSUs will only vest upon the achievement of certain specific revenue criteria and are subject to each employee's continued service to the Company through each applicable vesting date. If the financial performance metrics are not met within the time limits specified in the award agreements, the PSUs will be cancelled.
2014 Performance Stock Units
Pursuant to the 2007 Plan, during fiscal 2014, the Company granted 0.3 million target number of PSUs target number shares of PSUs to certain of the Company's executive officers. The number of shares to be issued upon vesting of PSUs range from 0 to 1.5 times the target number of PSUs granted depending on the relative performance of the Company's common stock price compared to the iShares North American Tech-Multimedia Networking ("IGN") Index over the span of one, two and three years of total shareholder returns. During the three months ended March 28, 2015, the Company released 0.2 million shares of PSUs, based on a payout of 1.5 times of the target number of PSUs.
The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
		Year Ended
		27-Dec-14
Infinera Volatility		49% - 50%
IGN Index Volatility		25%
Risk-free interest rate		0.66% - 0.71%
Correlation with IGN Index		0.6
Estimated fair value		$6.59 - $7.60
Additionally, pursuant to the 2007 Plan, during 2014, the Company granted 0.1 million shares of PSUs to several employees. These PSUs will only vest upon the achievement of certain specific performance criteria and are subject to each employee's continued service to the Company through each applicable vesting date. If the specific performance metrics are not met within the time limits specified in the award agreements, the PSUs will be cancelled.
2013 Performance Stock Units
Pursuant to the 2007 Plan, during fiscal 2013, the Company granted 0.6 million target number of PSUs to certain of its executive officers. The number of shares to be issued upon vesting of PSUs range from 0 to 1.5 times the target number of PSUs granted depending on the relative performance of the Company’s common stock price compared to the NASDAQ Telecom Composite Index over the span of one, two and three years of total shareholder returns. During the three months ended March 28, 2015, the Company released 0.2 million shares of PSUs, based on a payout of 1.5 times of the target number of PSUs.
The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
	Year Ended
	28-Dec-13
Infinera Volatility	55%
NASDAQ Telecom Composite Index Volatility	23%
Risk-free interest rate	0.42%
Correlation with NASDAQ Telecom Composite Index	0.56
Estimated fair value	$6.27 - $7.06
2012 Performance Stock Units
Pursuant to the 2007 Plan, during fiscal 2012, the Company granted 0.5 million shares of PSUs to certain of its executive officers. These PSUs will only vest upon the achievement of certain specific revenue and operating profit criteria and are subject to each named executive officer’s continued service to the Company. If the financial performance metrics are not met within the time limits specified in the award agreements, the PSUs will be canceled. During the three months ended March 28, 2015, the Company did not release any shares subject to these PSUs and were canceled as a result of the financial performance metrics not being met within the time limits specified in the award agreements.
Amortization of stock-based compensation related to PSUs in the three months ended March 28, 2015 and March 29, 2014 was approximately $0.9 million and $0.4 million, respectively.
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):
	28-Mar-15				27-Dec-14
Stock-based compensation effects in inventory	$	3,083			$	3,088
Stock-based compensation effects in deferred inventory cost	$	13			$	13
Stock-based compensation effects in fixed assets	$	113			$	119
	Three Months Ended
	28-Mar-15				29-Mar-14
Stock-based compensation effects included in net income (loss) before income taxes
Cost of revenue	$	482			$	452
Research and development	2,578				2,138
Sales and marketing	1,721				1,720
General and administration	1,666				1,530
	6,447				5,840
Cost of revenue – amortization from balance sheet (1)	761				832
Total stock-based compensation expense	$	7,208			$	6,672
(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	3 Months Ended
	Mar. 28, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Provision for income taxes for three months ended March 28, 2015 was $0.6 million on pre-tax income of $13.0 million. This compared to a tax provision of $0.2 million on a pre-tax loss of $4.1 million for the three months ended March 29, 2014. The increase in tax provision for the three months ended March 28, 2015 compared to the corresponding period in 2014 is attributed to stronger expected profitability in 2015, taxes being accrued in proportion to quarterly profit as it relates to total profit expected for the year, and higher foreign taxes due to an increase in cost-plus taxable profits. In all periods, the tax expense projected in the Company's effective tax rate primarily represents foreign taxes of the Company's overseas subsidiaries compensated on a cost-plus basis regardless of the level of consolidated earnings. Because of the Company's significant 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 nominal amounts of state taxes for which the losses are limited by statute. 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 our deferred tax assets will be recovered from future taxable income within the respective jurisdictions, and to the extent the Company believes that recovery does not meet the “more-likely-than-not” standard, it must establish a valuation allowance. 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 in determining the Company's provision for income taxes, its deferred tax assets and liabilities and any valuation allowance recorded against its net deferred tax assets. At March 28, 2015 and December 27, 2014, the Company's domestic net deferred tax assets were fully reserved with a valuation allowance because, based on the available evidence, management believed at that time it was more likely than not that the Company would not be able to utilize those deferred tax assets in the future.
	Notwithstanding the above, the Company has been profitable for four consecutive quarters beginning with the second quarter of 2014. If this trend continues and the Company is no longer in a cumulative loss position, it may consider the extent to which it can rely on forecasts of future income to support the realization of the Company's net U.S. deferred tax assets. These income forecasts would be considered with other positive and negative evidence, including the Company's 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 full or partial valuation allowance against its net U.S. deferred tax assets. 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.

Segment_Information

Segment Information	3 Months Ended
	Mar. 28, 2015
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
		28-Mar-15		29-Mar-14
	Americas:
	United States	$	127,003	$	110,691
	Other Americas	7,086		3,536
		134,089		114,227
	Europe, Middle East and Africa	45,879		25,613
	Asia Pacific and Japan	6,894		2,975
	Total revenue	$	186,862	$	142,815
	Property, plant and equipment, net
		28-Mar-15		December 27,
				2014
	United States	$	79,898	$	79,025
	Other Americas	154		196
	Europe, Middle East and Africa	797		1,477
	Asia Pacific and Japan	1,812		868
	Total property, plant and equipment, net	$	82,661	$	81,566

Guarantees

Guarantees	3 Months Ended
	Mar. 28, 2015
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 range from one to five yearsfrom date of acceptance for hardware and 90 days for software warranty. Upon delivery of the Company's products, we provide 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
		28-Mar-15			29-Mar-14
	Beginning balance	$	27,040		$	22,908
	Charges to operations	5,348			5,561
	Utilization	(1,818		)	(3,242		)
	Change in estimate(1)	(5,031		)	1,158
	Balance at the end of the period	$	25,539		$	26,385
	(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 and new parts. As our products mature over time, failure rates and repair costs generally decline leading to favorable changes in warranty reserves.

Litigation_and_Contingencies

Litigation and Contingencies	3 Months Ended
	Mar. 28, 2015
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingencies	Litigation and Contingencies
	Legal Matters
	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.
	Cambrian Science Patent Infringement Litigation
	On July 12, 2011, the Company was notified by Level 3 that Cambrian Science Corporation ("Cambrian") filed suit against Level 3 and six other defendants, including Cox Communications, Inc., XO Communications, LLC, Global Crossing Limited, 360Networks (USA), Inc., Integra Telecom, Inc. and IXC, Inc. dba Telekenex (collectively, the "Defendants") in the U.S. District Court for the Central District of California alleging infringement of patent no. 6,775,312 (the "'312 Patent") and requesting damages for such alleged infringement (the "Cambrian Claim"). The nature of the Cambrian Claim involves allegations of infringement of the '312 Patent resulting from the Defendants’ use of certain products and systems in the Defendants’ networks, including the Infinera DTN platform. On August 24, 2011, Cambrian amended the complaint to name the Company as a defendant. The Company assumed the defense of the Cambrian Claim and filed an answer to Cambrian’s complaint on September 21, 2011, in which the Company denied infringement of the '312 Patent and raised other defenses. Cambrian filed a second amended complaint on October 6, 2011, which included many of the same allegations as in the original complaint. The Company filed its answer to the second amended complaint on October 21, 2011, in which the Company maintained the same denials and defenses as in the Company’s initial answer. On December 23, 2011, the Company filed a motion requesting that the court stay the case with respect to each of the above-noted customer Defendants. Cambrian filed its opposition to the Company’s motion on December 30, 2011. The Company’s request was denied in the court’s decision on March 7, 2012. The Company presented evidence on the appropriate meanings of relevant key words used in the patent claims during a claim construction hearing on November 20, 2012.
	On June 17, 2013, the court issued an order regarding claim construction, in which the court agreed with almost all of the Company’s proposed claim constructions. On October 17, 2013, the parties met for a court-mandated mediation. On April 24, 2014, the Company filed two motions for summary judgment relating to non-infringement and Cambrian’s claim to an earlier date of invention. The court held a hearing on the summary judgment motions on June 9, 2014. On July 2, 2014, the court granted the Company's motion for summary judgment on non-infringement and entered a final judgment of non-infringement of the '312 Patent. On August 1, 2014, Cambrian filed a notice of appeal regarding the ruling of non-infringement to the Court of Appeals for the Federal Circuit and Cambrian's appeal brief was filed on November 6, 2014. The Company filed its responsive brief on January 5, 2015, and on February 5, 2015, Cambrian filed their reply brief. Oral argument of this appeal has been set for May 5, 2015. After the court granted summary judgment, the Company sought to recover certain costs and attorney's fees from Cambrian.
	As of March 28, 2015, the Company concluded that the likelihood of a loss with respect to this suit was remote and the amount of any loss would be insignificant. The Company does not believe the outcome of this matter will have a material adverse effect on the Company's business, consolidated financial position, results of operations, or cash flows. Factors that the Company considered in the determination of the likelihood of a loss and the estimate of that loss in respect to this matter included the merits of the case, the district court granting the Company's motion for summary judgment for non-infringement, the entry of final judgment of non-infringement and the current stage of the litigation. However, the outcome of such legal matters is inherently unpredictable and subject to uncertainty.
	Loss Contingencies
	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 March 28, 2015, the Company has accrued an immaterial amount for such liabilities.

Subsequent_Event_Notes

Subsequent Event (Notes)	3 Months Ended
	Mar. 28, 2015
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event
	On April 8, 2015, the Company issued a press release in Sweden and in the U.S. announcing the Company’s intent to combine with Sweden-based Transmode AB, a Swedish company ("Transmode"), pursuant to a public exchange offer to acquire all issued and outstanding shares of Transmode (the “Offer”). In the Offer, the Company is offering Transmode’s shareholders cash and common stock as follows: (i) with respect to approximately 73.8 percent of the Transmode shares exchanged by each shareholder, approximately 0.6376 new shares of Infinera’s common stock per Transmode share; and (ii) with respect to the remaining approximately 26.2 percent of the Transmode shares exchanged by such shareholder, Swedish kronor ("SEK") 107.05 in cash per Transmode share. The board of directors of Transmode has unanimously recommended that Transmode’s shareholders accept the Offer. The foregoing reflects the payment by Transmode to its shareholders of a dividend of SEK 1.95 per share on April 23, 2015. If Transmode pays another dividend or makes any other distributions to its shareholders, with a record date occurring prior to the settlement of the Offer, the Offer consideration will be reduced accordingly.
	If the Offer is accepted in its entirety, 13,037,699 shares of Infinera’s common stock ("Infinera Shares") will be issued under the Offer, corresponding to approximately 10.1 percent of Infinera’s shares outstanding. Following completion of the Offer, if accepted in its entirety, former Transmode shareholders would hold Infinera Shares representing approximately 9.2 percent of the outstanding shares of and voting power in the combined company and approximately 8.7 percent of the combined company on a fully diluted basis. The cash portion of the Offer totals approximately $88.9 million and will be financed through existing cash resources. The foregoing numbers in this paragraph are based on 27,709,236 outstanding shares in Transmode as of March 31, 2015 (excluding 79,440 of its own shares held in treasury by Transmode) and 129,093,644 outstanding shares in the Company as of March 28, 2015.
	On April 9, 2015, the Company entered into a foreign currency forward contract with a notional amount of SEK 831 million ($95.3 million) at an exchange rate of 8.7402 to hedge currency exposures associated with the cash portion of the Offer. In addition, changes in the fair value of this forward contract will impact the Company's financial statements for the interim reporting periods prior to the close of the Offer.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 28, 2015
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 March 28, 2015											As of December 27, 2014
		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	$	39,633	$	—		$	—		$	39,633		$	21,478	$	—		$	—	$	21,478
	Certificates of deposit	—		9,465			—			9,465			—		8,060			—		8,060
	Commercial paper	—		21,690			—			21,690			—		46,072			—		46,072
	Corporate bonds	—		223,238			—			223,238			—		235,285			—		235,285
	U.S. agency notes	—		14,508			—			14,508			—		—			—		—
	U.S. treasuries	16,014		—			—			16,014			14,810		—			—		14,810
	Foreign currency exchange forward contracts	—		—			—			—			—		—			—		—
	Total assets	$	55,647	$	268,901		$	—		$	324,548		$	36,288	$	289,417		$	—	$	325,705
	Liabilities
	Foreign currency exchange forward contracts	$	—	$	(117	)	$	—		$	(117	)	$	—	$	(64	)	$	—	$	(64	)
Investments at Fair Value	Investments at fair value were as follows (in thousands):
		28-Mar-15
		Adjusted Amortized Cost		Gross Unrealized Gains			Gross Unrealized			Fair Value
							Losses
	Money market funds	$	39,633	$	—		$	—		$	39,633
	Certificates of deposit	9,460		5			—			9,465
	Commercial paper	21,691		—			(1		)	21,690
	Corporate bonds	223,425		12			(199		)	223,238
	U.S. agency notes	14,507		5			(4		)	14,508
	U.S. treasuries	16,009		9			(4		)	16,014
	Total available-for-sale investments	$	324,725	$	31		$	(208	)	$	324,548
		December 27, 2014
		Adjusted Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	Money market funds	$	21,478	$	—		$	—		$	21,478
	Certificates of deposit	8,060		—			—			8,060
	Commercial paper	46,073		—			(1		)	46,072
	Corporate bonds	235,713		2			(430		)	235,285
	U.S. treasuries	14,825		1			(16		)	14,810
	Total available-for-sale investments	$	326,149	$	3		$	(447	)	$	325,705

Derivative_Instruments_Tables

Derivative Instruments (Tables)	3 Months Ended
	Mar. 28, 2015
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 March 28, 2015					As of December 27, 2014
		Gross Notional(1)		Other			Gross Notional(1)		Other
				Accrued					Accrued
				Liabilities					Liabilities
	Foreign currency exchange forward contracts
	Related to euro denominated receivables	$	22,350	$	(107	)	$	34,445	$	(53	)
	Related to British pound denominated receivables	1,590		(5		)	2,678		(9		)
	Related to restricted cash	1,103		(5		)	1,236		(2		)
		$	25,043	$	(117	)	$	38,359	$	(64	)
	(1)	Represents the face amounts of forward contracts that were outstanding as of the period noted.

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 28, 2015
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):
		28-Mar-15			27-Dec-14
	Inventory:
	Raw materials	$	22,372		$	15,169
	Work in process	45,871			50,046
	Finished goods (1)	88,952			81,285
	Total inventory	$	157,195		$	146,500
	Property, plant and equipment, net:
	Computer hardware	$	9,584		$	8,785
	Computer software(2)	18,705			17,684
	Laboratory and manufacturing equipment	166,514			162,004
	Furniture and fixtures	1,433			1,340
	Leasehold improvements	38,450			37,825
	Construction in progress	15,340			14,726
	Subtotal	$	250,026		$	242,364
	Less accumulated depreciation and amortization	(167,365		)	(160,798		)
	Total property, plant and equipment, net	$	82,661		$	81,566
	Accrued expenses:
	Loss contingency related to non-cancelable purchase commitments	$	5,048		$	5,390
	Professional and other consulting fees	2,631			1,831
	Taxes payable	2,853			3,993
	Royalties	3,009			2,648
	Accrued rebate and customer prepay liability	1,026			941
	Accrued interest on convertible senior notes	875			219
	Other accrued expenses	12,619			11,419
	Total accrued expenses	$	28,061		$	26,441
	(1)	Included in finished goods inventory at March 28, 2015 and December 27, 2014 were $12.9 million and $10.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
	(2)	Included in computer software at March 28, 2015 and December 27, 2014 were $7.9 million and $7.9 million, respectively, related to an enterprise resource planning ("ERP") system that the Company implemented during 2012. The unamortized ERP costs at March 28, 2015 and December 27, 2014 were $4.9 million and $5.2 million, respectively.
Schedule of Components of Restricted Cash	The following table sets forth the Company's restricted cash (in thousands):
		28-Mar-15			27-Dec-14
	Restricted cash related to outstanding standby letters of credit
	Value added tax license	$	1,177		$	1,309
	Customer proposal guarantee	2,832			3,074
	Property leases	699			699
	Other	400			378
	Total restricted cash	$	5,108		$	5,460

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 28, 2015
Equity [Abstract]
Summary of Changes in Accumulated Other Comprehensive Income (Loss)	Other comprehensive loss includes certain changes in equity that are excluded from net income (loss). The following table sets forth the changes in accumulated other comprehensive loss by component for the three months ended March 28, 2015 (in thousands):
		Unrealized Gain			Foreign			Accumulated			Total
		on Other			Currency Translation			Tax Effect
		Available-for-Sale
		Securities
	Balance at December 27, 2014	$	(444	)	$	(3,414	)	$	(760	)	$	(4,618	)
	Net current-period other comprehensive loss	267			(159		)	—			108
	Balance at March 28, 2015	$	(177	)	$	(3,573	)	$	(760	)	$	(4,510	)

Basic_and_Diluted_Net_Income_L1

Basic and Diluted Net Income (Loss) Per Common Share (Tables)	3 Months Ended
	Mar. 28, 2015
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
		28-Mar-15			29-Mar-14
	Numerator:
	Net income (loss)	$	12,366		$	(4,374	)
	Denominator:
	Basic weighted average common shares outstanding	127,840			121,352
	Effect of dilutive securities:
	Employee equity plans	6,569			—
	Assumed conversion of convertible senior notes from conversion spread	2,895			—
	Diluted weighted average common shares outstanding	137,304			121,352
	Net income (loss) per common share
	Basic	$	0.1		$	(0.04	)
	Diluted	$	0.09		$	(0.04	)
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 would have been anti-dilutive (in thousands):
		Three Months Ended
		28-Mar-15		29-Mar-14
	Stock options	10		6,135
	Restricted stock units	1,505		5,386
	Performance stock units	292		763
	Employee stock purchase plan shares	415		431
	Total	2,222		12,715

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	3 Months Ended
	Mar. 28, 2015
Debt Disclosure [Abstract]
Components of Convertible Senior Notes	The net carrying amounts of the debt obligation were as follows (in thousands):
		28-Mar-15			December 27, 2014
	Principal	$	150,000		$	150,000
	Unamortized discount (1)	(31,049		)	(33,106		)
	Unamortized issuance cost (1)	(2,671		)	(2,848		)
	Net carrying amount	116,280			114,046
	(1)	Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately three years.
Interest expense recognized related to Notes	The following table sets forth total interest expense recognized related to the Notes (in thousands):
		Three Months Ended
		28-Mar-15			29-Mar-14
	Contractual interest expense	$	656		$	657
	Amortization of debt issuance costs	177			160
	Amortization of debt discount	2,057			1,860
	Total interest expense	$	2,890		$	2,677

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 28, 2015
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			Weighted-Average			Aggregate
		Options			Exercise			Intrinsic
					Price			Value
					Per Share
	Outstanding at December 27, 2014	4,298			$	7.29		$	32,833
	Stock options granted	—			$	—
	Stock options exercised	(559	)		$	6.74		$	5,789
	Stock options canceled	—			$	—
	Outstanding at March 28, 2015	3,739			$	7.37		$	45,711
	Vested and expected to vest as of March 28, 2015	3,737						$	45,690
	Exercisable at March 28, 2015	3,687			$	7.36		$	45,097
Summary of Company's Equity Award Activity - RSUs
		Number of			Weighted-			Aggregate
		Restricted			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 27, 2014	6,042			$	8.14		$	90,085
	RSUs granted	1,581			$	17.95
	RSUs released	(1,393	)		$	7.97		$	22,807
	RSUs canceled	(78	)		$	8.58
	Outstanding at March 28, 2015	6,152			$	10.69		$	120,514
	Expected to vest at March 28, 2015	5,798						$	113,574
Summary of Company's Equity Award Activity - PSUs
		Number of			Weighted-			Aggregate
		Performance			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 27, 2014	876			$	7.49		$	13,067
	PSUs granted	438			$	14.97
	PSUs released	(386	)		$	6.67		$	6,585
	PSUs canceled	(191	)		$	7.88
	Outstanding at March 28, 2015	737			$	12.14		$	14,444
	Expected to vest at March 28, 2015	703						$	13,764
	The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
			Year Ended
			27-Dec-14
	Infinera Volatility		49% - 50%
	IGN Index Volatility		25%
	Risk-free interest rate		0.66% - 0.71%
	Correlation with IGN Index		0.6
	Estimated fair value		$6.59 - $7.60
	The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
			Three Months Ended
			28-Mar-15
	Infinera Volatility		48%
	SPGIIPTR Index Volatility		18% - 19%
	Risk-free interest rate		0.97% - 1.10%
	Correlation with SPGIIPTR Index		0.52
	Estimated fair value		$18.08 - $19.29
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 March 28, 2015. 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			Weighted-
		Compensation			Average Period
		Expense, Net			(in years)
	Stock options	170			1.5
	RSUs	48,111			2.7
	PSUs	7,083			1.6
Ranges of Estimated Values of Stock Options and Performance-Based Stock Options Granted	The estimated values of stock options, as well as assumptions used in calculating these values were based on estimates as follows (expense amounts in thousands):
		Three Months Ended
	Employee and Director Stock Options	28-Mar-15		29-Mar-14
	Volatility	N/A		52%
	Risk-free interest rate	N/A		1.30%
	Expected life	N/A		4.3 years
	Estimated fair value	N/A		$3.85
	Total stock-based compensation expense	$70		$388
	_________________
	N/A	Not applicable because the Company did not grant any stock options during the period.
Estimated Fair Value of ESPP Shares	The fair value of the ESPP shares was estimated at the date of grant using the following assumptions (expense amounts in thousands):
		Three Months Ended
	Employee Stock Purchase Plan	28-Mar-15		29-Mar-14
	Volatility	53%		51%
	Risk-free interest rate	0.13%		0.11%
	Expected life	0.5 years		0.5 years
	Estimated fair value	$5.15		$2.57
	Total stock-based compensation expense	$1,051		$791
Schedule of Share-based Payment Award, Valuation Assumptions	The ranges of estimated values of the PSUs granted, as well as assumptions used in calculating these values were based on estimates as follows:
		Year Ended
		28-Dec-13
	Infinera Volatility	55%
	NASDAQ Telecom Composite Index Volatility	23%
	Risk-free interest rate	0.42%
	Correlation with NASDAQ Telecom Composite Index	0.56
	Estimated fair value	$6.27 - $7.06
Schedule of Additional Share-based Payment Award, Valuation Assumptions
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):
		28-Mar-15				27-Dec-14
	Stock-based compensation effects in inventory	$	3,083			$	3,088
	Stock-based compensation effects in deferred inventory cost	$	13			$	13
	Stock-based compensation effects in fixed assets	$	113			$	119
		Three Months Ended
		28-Mar-15				29-Mar-14
	Stock-based compensation effects included in net income (loss) before income taxes
	Cost of revenue	$	482			$	452
	Research and development	2,578				2,138
	Sales and marketing	1,721				1,720
	General and administration	1,666				1,530
		6,447				5,840
	Cost of revenue – amortization from balance sheet (1)	761				832
	Total stock-based compensation expense	$	7,208			$	6,672
	(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)	3 Months Ended
	Mar. 28, 2015
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
		28-Mar-15		29-Mar-14
	Americas:
	United States	$	127,003	$	110,691
	Other Americas	7,086		3,536
		134,089		114,227
	Europe, Middle East and Africa	45,879		25,613
	Asia Pacific and Japan	6,894		2,975
	Total revenue	$	186,862	$	142,815
Property, Plant and Equipment, Net	Property, plant and equipment, net
		28-Mar-15		December 27,
				2014
	United States	$	79,898	$	79,025
	Other Americas	154		196
	Europe, Middle East and Africa	797		1,477
	Asia Pacific and Japan	1,812		868
	Total property, plant and equipment, net	$	82,661	$	81,566

Guarantees_Tables

Guarantees (Tables)	3 Months Ended
	Mar. 28, 2015
Guarantees [Abstract]
Activity Related to Product Warranty	Activity related to product warranty was as follows (in thousands):
		Three Months Ended
		28-Mar-15			29-Mar-14
	Beginning balance	$	27,040		$	22,908
	Charges to operations	5,348			5,561
	Utilization	(1,818		)	(3,242		)
	Change in estimate(1)	(5,031		)	1,158
	Balance at the end of the period	$	25,539		$	26,385

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies Basis of Presentation and Significant Accounting Polices (Details)	3 Months Ended
	Mar. 28, 2015	Mar. 29, 2014
Concentration Risk [Line Items]
NumberOfMajorCustomersRepresentingTotalRevenue	2	2
Sales Revenue, Net [Member] | Customer One [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	18.00%	21.00%
Sales Revenue, Net [Member] | Customer Two [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	16.00%	16.00%

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 28, 2015	Dec. 27, 2014
Fair Value Disclosures [Abstract]
Available-for-sale investments	24 months
Cash	$79	$59.70

Fair_Value_Measurements_Assets

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (Fair Value, Measurements, Recurring, USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Assets
Total Assets	$324,548	$325,705
Money market funds
Assets
Total Assets	39,633	21,478
Certificates of deposit
Assets
Total Assets	9,465	8,060
Commercial paper
Assets
Total Assets	21,690	46,072
Corporate bonds
Assets
Total Assets	223,238	235,285
U.S. agency notes
Assets
Total Assets	14,508	0
U.S. treasuries
Assets
Total Assets	16,014	14,810
Foreign currency exchange forward contracts
Assets
Total Assets	0	0
Liabilities
Total Liabilities	-117	-64
Level 1
Assets
Total Assets	55,647	36,288
Level 1 | Money market funds
Assets
Total Assets	39,633	21,478
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	16,014	14,810
Level 1 | Foreign currency exchange forward contracts
Assets
Total Assets	0	0
Liabilities
Total Liabilities	0	0
Level 2
Assets
Total Assets	268,901	289,417
Level 2 | Money market funds
Assets
Total Assets	0	0
Level 2 | Certificates of deposit
Assets
Total Assets	9,465	8,060
Level 2 | Commercial paper
Assets
Total Assets	21,690	46,072
Level 2 | Corporate bonds
Assets
Total Assets	223,238	235,285
Level 2 | U.S. agency notes
Assets
Total Assets	14,508	0
Level 2 | U.S. treasuries
Assets
Total Assets	0	0
Level 2 | Foreign currency exchange forward contracts
Assets
Total Assets	0	0
Liabilities
Total Liabilities	-117	-64
Level 3
Assets
Total Assets	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
Level 3 | Foreign currency exchange forward contracts
Assets
Total Assets	0	0
Liabilities
Total Liabilities	$0	$0

Fair_Value_Measurements_Invest

Fair Value Measurements - Investments at Fair Value (Details) (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	$324,725	$326,149
Gross Unrealized Gains	31	3
Gross Unrealized Losses	-208	-447
Fair Value	324,548	325,705
Money market funds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	39,633	21,478
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	39,633	21,478
Certificates of deposit
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	9,460	8,060
Gross Unrealized Gains	5	0
Gross Unrealized Losses	0	0
Fair Value	9,465	8,060
Commercial paper
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	21,691	46,073
Gross Unrealized Gains	0	0
Gross Unrealized Losses	-1	-1
Fair Value	21,690	46,072
Corporate bonds
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	223,425	235,713
Gross Unrealized Gains	12	2
Gross Unrealized Losses	-199	-430
Fair Value	223,238	235,285
U.S. agency notes
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	14,507
Gross Unrealized Gains	5
Gross Unrealized Losses	-4
Fair Value	14,508
U.S. treasuries
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Adjusted Amortized Cost	16,009	14,825
Gross Unrealized Gains	9	1
Gross Unrealized Losses	-4	-16
Fair Value	$16,014	$14,810

Costmethod_Investment_Addition

Cost-method Investment - Additional Information (Details) (USD $)	3 Months Ended
	Mar. 28, 2015	Dec. 27, 2014
Investments, All Other Investments [Abstract]
Cost-method investment	$14,500,000	$14,500,000
Less than percent of voting securities	20.00%
Impairment charge on cost-method investments	$0

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
British pound denominated receivables and typically maturities period	35 days
Euro denominated forward contracts maturity period	35 days
Before-tax effect of foreign currency exchange forward contracts not designated as hedging instruments, gain (loss)	$3.30	($1.20)

Derivative_Instruments_Fair_Va

Derivative Instruments - Fair Value of Derivative Instruments Not Designated as Hedging Activities (Details) (USD $)	Mar. 28, 2015		Dec. 27, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]
Forward contract notional amount	$25,043	[1]	$38,359	[1]
Other Accrued Liabilities	-117		-64
Designated as Hedging Instrument | Euro Denominated Exchange Forward Contracts Receivables
Derivative [Line Items]
Forward contract notional amount	22,350	[1]	34,445	[1]
Other Accrued Liabilities	-107		-53
Designated as Hedging Instrument | GBP Denominated Exchange Forward Contracts Receivables
Derivative [Line Items]
Forward contract notional amount	1,590	[1]	2,678	[1]
Other Accrued Liabilities	-5		-9
Designated as Hedging Instrument | Foreign Currency Exchange Restricted Cash Forward Contracts
Derivative [Line Items]
Forward contract notional amount	1,103	[1]	1,236	[1]
Other Accrued Liabilities	($5)		($2)
[1]	Represents the face amounts of forward contracts that were outstanding as of the period noted.

Balance_Sheet_Details_Selected

Balance Sheet Details - Selected Balance Sheet Items (Details) (USD $)	Mar. 28, 2015		Dec. 27, 2014
Inventory:
Raw materials	$22,372,000		$15,169,000
Work in process	45,871,000		50,046,000
Finished goods	88,952,000	[1]	81,285,000	[1]
Total inventory	157,195,000		146,500,000
Property, plant and equipment, net:
Property, plant and equipment, gross	250,026,000		242,364,000
Less accumulated depreciation and amortization	-167,365,000		-160,798,000
Total property, plant and equipment, net	82,661,000		81,566,000
Accrued expenses:
Loss contingency related to non-cancelable purchase commitments	5,048,000		5,390,000
Professional and other consulting fees	2,631,000		1,831,000
Taxes payable	2,853,000		3,993,000
Royalties	3,009,000		2,648,000
Accrued rebate and customer prepay liability	1,026,000		941,000
Accrued interest on convertible senior notes	875,000		219,000
Other accrued expenses	12,619,000		11,419,000
Total accrued expenses	28,061,000		26,441,000
Enterprise Resource Planning Systems
Property, plant and equipment, net:
Property, plant and equipment, gross	7,900,000		7,900,000
Total property, plant and equipment, net	4,900,000		5,200,000
Computer hardware
Property, plant and equipment, net:
Property, plant and equipment, gross	9,584,000		8,785,000
Computer software
Property, plant and equipment, net:
Property, plant and equipment, gross	18,705,000	[2]	17,684,000	[2]
Laboratory and manufacturing equipment
Property, plant and equipment, net:
Property, plant and equipment, gross	166,514,000		162,004,000
Furniture and fixtures
Property, plant and equipment, net:
Property, plant and equipment, gross	1,433,000		1,340,000
Leasehold improvements
Property, plant and equipment, net:
Property, plant and equipment, gross	38,450,000		37,825,000
Construction in progress
Property, plant and equipment, net:
Property, plant and equipment, gross	15,340,000		14,726,000
Customer Locations
Accrued expenses:
Inventory awaiting customer acceptance	$12,900,000		$10,200,000
[1]	Included in finished goods inventory at March 28, 2015 and December 27, 2014 were $12.9 million and $10.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
[2]	Included in computer software at March 28, 2015 and December 27, 2014 were $7.9 million and $7.9 million, respectively, related to an enterprise resource planning ("ERP") system that the Company implemented during 2012. The unamortized ERP costs at March 28, 2015 and December 27, 2014 were $4.9 million and $5.2 million, respectively.

Balance_Sheet_Details_Restrict

Balance Sheet Details - Restricted Cash (Details) (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Value added tax license	$1,177	$1,309
Customer proposal guarantee	2,832	3,074
Property leases	699	699
Other	400	378
Long-term restricted cash	$5,108	$5,460

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss - Summary of Changes in Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	($4,618)
Net current-period other comprehensive loss	108	274
Ending balance	-4,510
Unrealized Gain on Other Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	-444
Net current-period other comprehensive loss	267
Ending balance	-177
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	-3,414
Net current-period other comprehensive loss	-159
Ending balance	-3,573
Accumulated Tax Effect
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	-760
Net current-period other comprehensive loss	0
Ending balance	($760)

Basic_and_Diluted_Net_Income_L2

Basic and Diluted Net Income (Loss) Per Common Share - Computation of Net Loss Per Common Share Basic and Diluted (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Earnings Per Share [Abstract]
Net income (loss)	$12,366	($4,374)
Basic weighted average common shares outstanding (in shares)	127,840	121,352
Employee equity plans (in shares)	6,569	0
Assumed conversion of convertible senior notes from conversion spread (in shares)	2,895	0
Diluted weighted average common shares outstanding (in shares)	137,304	121,352
Net income (loss) per common share
Basic (in usd per share)	$0.10	($0.04)
Diluted (in usd per share)	$0.09	($0.04)

Basic_and_Diluted_Net_Income_L3

Basic and Diluted Net Income (Loss) Per Common Share - Antidilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	2,222	12,715
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	10	6,135
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	1,505	5,386
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	292	763
Employee stock purchase plan shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share computation (in shares)	415	431

Convertible_Senior_Notes_Addit

Convertible Senior Notes - Additional Information (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended
	31-May-13	Mar. 28, 2015		Dec. 28, 2013	Mar. 27, 2015	Dec. 27, 2014		Mar. 29, 2014	30-May-13
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt Instrument Remaining Term		3 years
Purchase price as a percentage on principal amount of the notes upon the occurrence of a fundamental change	100.00%
Unamortized discount		$31,049,000	[1]			$33,106,000	[1]
Total estimated fair value of the notes		245,400,000
Closing price of common stock (in usd per share)					$19.59
1.75% Convertible Senior Notes Due June 1, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt instrument issued									150,000,000
Debt instrument interest percentage		1.75%						1.75%	1.75%
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)									$12.58
Debt instrument, convertible, if-converted value in excess of principal		83,600,000
Debt issuance cost		5,500,000
Deferred tax liability		17,000,000
Additional effective rate of interest to be used on amortized carrying value		10.23%						10.23%
Convertible Senior Notes, Conversion Circumstance One [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Convertible threshold trading days	20 days
Convertible threshold consecutive trading days	30 days
Convertible threshold minimum percentage	130.00%
Convertible Senior Notes, Conversion Circumstance Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Convertible threshold consecutive trading days	5 days
Convertible threshold business days	5
Debt instrument, convertible, if-converted value in excess of principal	1,000
Convertible, threshold maximum percentage	98.00%
[1]	Unamortized debt conversion discount and issuance costs will be amortized over the remaining life of the Notes, which is approximately three years.

Convertible_Senior_Notes_Compo

Convertible Senior Notes - Components of Convertible Senior Notes (Details) (USD $)	Mar. 28, 2015		Dec. 27, 2014		30-May-13
Debt Instrument [Line Items]
Unamortized discount	$31,049,000	[1]	$33,106,000	[1]
Unamortized issuance cost	-2,671,000	[1]	-2,848,000	[1]
1.75% Convertible Senior Notes Due June 1, 2018
Debt Instrument [Line Items]
Principal amount					150,000,000
Initial transaction amount and net carrying amount, APIC	43,300,000		43,341,000
Convertible Debt, Noncurrent	116,280,000		114,046,000
1.75% Convertible Senior Notes Due June 1, 2018 | Additional Paid-in Capital
Debt Instrument [Line Items]
Equity component	45,000,000		45,000,000
Debt issuance cost	1,700,000		-1,659,000
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 three years.

Convertible_Senior_Notes_Inter

Convertible Senior Notes - Interest Expense Recognized Related to Notes Prior to Capitalization of Interest (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Debt Disclosure [Abstract]
Contractual interest expense	$656	$657
Amortization of debt issuance costs	177	160
Amortization of debt discount	2,057	1,860
Total interest expense	$2,890	$2,677

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Details) (USD $)	3 Months Ended	12 Months Ended		3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 28, 2015	Dec. 28, 2013	Dec. 27, 2014	Mar. 29, 2014	Mar. 27, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted options to employees to purchase shares of common stock (in shares)	15,700,000
Closing price of common stock (in usd per share)					$19.59
SPGIIPTR Index
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)	200,000
NASDAQ Telecom Composite Index
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)		600,000
IGN Index
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)			300,000
Performance Stock Unit Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization of stock-based compensation	0.9			$0.40
Shares of PSUs to executive officers (in shares)	100,000
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)	438,000
PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	0
PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	1.5
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)	1,581,000
Amortization of stock-based compensation	5.2			$5.10
Two Thousand And Seven Equity Incentive Plan [Member] | NASDAQ Telecom Composite Index | 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 [Member] | NASDAQ Telecom Composite Index | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	1.5
Two Thousand And Seven Equity Incentive Plan [Member] | IGN Index | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	1.5

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Company's Equity Award Activity - Options (Details) (Stock options, USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 28, 2015
Stock options
Number of Stock Options
Number of Options, beginning balance (in shares)	4,298
Number of options, granted (in shares)	0
Number of Options, exercised (in shares)	-559
Number of Options, canceled (in shares)	0
Number of Options, ending balance (in shares)	3,739
Number of Options, vested and expected to vest (in shares)	3,737
Number of Options, exercisable (in shares)	3,687
Weighted-Average Exercise Price Per Share
Weighted-Average Exercise Price Per Share, beginning balance (in usd per share)	$7.29
Weighted-Average Exercise Per Share, Options granted (in usd per share)	$0
Weighted-Average Exercise Price Per Share, Options exercised (in usd per share)	$6.74
Weighted-Average Exercise Price Per Share, Options canceled (in usd per share)	$0
Weighted-Average Exercise Price Per Share, ending balance (in usd per share)	$7.37
Average Exercise Price Per Share, Exercisable (in usd per share)	$7.36
Aggregate Intrinsic Value
Aggregate Intrinsic Value, beginning balance	$32,833
Aggregate Intrinsic Value, Options exercised	5,789
Aggregate Intrinsic Value, ending balance	45,711
Aggregate Intrinsic Value, Vested and expected to vest	45,690
Aggregate Intrinsic Value, Exercisable	$45,097

Stockholders_Equity_Summary_of1

Stockholders' Equity - Summary of Company's Equity Award Activity - RSUs (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 28, 2015
Restricted Stock Units
Number of Restricted Stock Units
Number of Restricted/Performance Stock Units, beginning balance (in shares)	6,042
Number of shares available for grant cost (in shares)	1,581
Number of Restricted Stock Units, released (in shares)	-1,393
Number of Restricted Stock Units, canceled (in shares)	-78
Number of Restricted/Performance Stock Units, ending balance (in shares)	6,152
Number of Restricted Stock Units, Expected to vest (in shares)	5,798
Weighted- Average Grant Date Fair Value Per Share
Weighted-Average Grant Date Fair Value Per Share, beginning balance (in usd per share)	$8.14
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$17.95
Weighted-Average Grant Date Fair Value Per Share, released (in usd per share)	$7.97
Weighted-Average Grant Date Fair Value Per Share, canceled (in usd per share)	$8.58
Weighted-Average Grant Date Fair Value Per Share, ending balance (in usd per share)	$10.69
Aggregate Intrinsic Value
Aggregate Intrinsic Value, beginning balance	$90,085
Aggregate Intrinsic Value, RSUs released	22,807
Aggregate Intrinsic Value, ending balance	120,514
Aggregate Intrinsic Value, Expected to vest	$113,574
Fiscal Year 2013 Grant
Number of Restricted Stock Units
Number of Restricted Stock Units, released (in shares)	-200

Stockholders_Equity_Summary_of2

Stockholders' Equity - Summary of Company's Equity Award Activity - PSUs (Details) (USD $)	3 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 29, 2014	Dec. 27, 2014	Dec. 29, 2012	Mar. 28, 2015	Dec. 28, 2013	Mar. 27, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock (in usd per share)						$19.59
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Portion Of Performance Stock Units Not Related To Index		100,000	500,000
Volatility	52.00%
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility				48.00%	55.00%
Number of Performance Stock Units
Number of Restricted/Performance Stock Units, beginning balance (in shares)				876,000
Number of shares available for grant cost (in shares)				438,000
Number of Restricted Stock Units, released (in shares)				-386,000
Number of Restricted Stock Units, canceled (in shares)				-191,000
Number of Restricted/Performance Stock Units, ending balance (in shares)		876,000		737,000
Number of Restricted Stock Units, Expected to vest (in shares)				703,000
Weighted- Average Grant Date Fair Value Per Share
Weighted-Average Grant Date Fair Value Per Share, beginning balance (in usd per share)				$7.49
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)				$14.97
Weighted-Average Grant Date Fair Value Per Share, released (in usd per share)				$6.67
Weighted-Average Grant Date Fair Value Per Share, canceled (in usd per share)				$7.88
Weighted-Average Grant Date Fair Value Per Share, ending balance (in usd per share)		7.49		$12.14
Aggregate Intrinsic Value
Aggregate Intrinsic Value, beginning balance				$13,067
Aggregate Intrinsic Value, PSUs released				6,585
Aggregate Intrinsic Value, ending balance		13,067		14,444
Aggregate Intrinsic Value, Expected to vest				$13,764
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Correction with NASDAQ Telecom Composite Index		60.00%		52.00%
Performance Stock Unit Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of PSUs to executive officers (in shares)				100,000
Minimum | Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
infn_SharebasedCompensationArrangementbySharebasedPaymentAwardFairValueAssumptionsSPGIIPTRIndexExpectedVolatilityRate				18.00%
Ranges of number of shares issued on vesting of PSUs				0
Volatility		49.00%
Weighted- Average Grant Date Fair Value Per Share
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)		6.59		$18.08	6.27
Maximum | Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
infn_SharebasedCompensationArrangementbySharebasedPaymentAwardFairValueAssumptionsSPGIIPTRIndexExpectedVolatilityRate				19.00%
Ranges of number of shares issued on vesting of PSUs				1.5
Volatility		50.00%
Weighted- Average Grant Date Fair Value Per Share
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)		7.6		$19.29	7.06
Fiscal Year 2014 Grant [Member]
Number of Performance Stock Units
Number of Restricted Stock Units, released (in shares)				-200,000
Fiscal Year 2013 Grant
Number of Performance Stock Units
Number of Restricted Stock Units, released (in shares)				-200,000
SPGIIPTR Index
Number of Performance Stock Units
Number of shares available for grant cost (in shares)				200,000
IGN Index
Number of Performance Stock Units
Number of shares available for grant cost (in shares)		300,000
NASDAQ Telecom Composite Index
Number of Performance Stock Units
Number of shares available for grant cost (in shares)					600,000
Two Thousand And Seven Equity Incentive Plan [Member] | IGN Index | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs				1.5
Two Thousand And Seven Equity Incentive Plan [Member] | NASDAQ Telecom Composite Index | 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 [Member] | NASDAQ Telecom Composite Index | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs				1.5

Stockholders_Equity_Total_Stoc

Stockholders' Equity - Total Stock Based Compensation Cost for Instruments Granted but Not Yet Amortized (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, Unrecognized Compensation Expense, Net	$170
Stock options, Weighted-Average Period (in years)	1 year 5 months 16 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Expense, Net	48,111
Weighted-Average Period (in years)	2 years 8 months 12 days
Number of shares available for grant cost (in shares)	1,581
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Expense, Net	$7,083
Weighted-Average Period (in years)	1 year 7 months 6 days
Number of shares available for grant cost (in shares)	438
IGN Index
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant cost (in shares)		300

Stockholders_Equity_Ranges_of_

Stockholders' Equity - Ranges of Estimated Values of Stock Options and Performance-Based Stock Options Granted (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014	Dec. 27, 2014	Dec. 29, 2012	Dec. 28, 2013	Mar. 27, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Portion Of Performance Stock Units Not Related To Index			0.1	0.5
Closing price of common stock (in usd per share)						$19.59
Volatility		52.00%
Estimated fair value (in usd per share)		$3.85
Risk-free interest rate		1.30%
Expected life		4 years 3 months 18 days
Stock-based compensation expense	$7,208	$6,672
Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	70	388
Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility	53.00%	51.00%
Estimated fair value (in usd per share)	$5.15	$2.57
Risk-free interest rate	0.13%	0.11%
Expected life	6 months	6 months
Stock-based compensation expense	$1,051	$791
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$14.97
Volatility	48.00%				55.00%
NASDAQ Telecom Composite Index Volatility					23.00%
Risk-free interest rate					0.42%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, NASDAQ Telecom Composite Index, Expected Volatility Rate			25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Correction with NASDAQ Telecom Composite Index	52.00%		60.00%
Correlation with NASDAQ Telecom Composite Index					56.00%
Performance stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	0
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$18.08		6.59		6.27
Volatility			49.00%
Risk-free interest rate			0.66%
Performance stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ranges of number of shares issued on vesting of PSUs	1.5
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$19.29		7.6		7.06
Volatility			50.00%
Risk-free interest rate			0.71%
Performance Stock Unit Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of PSUs to executive officers (in shares)	0.1

Stockholders_Equity_Estimated_

Stockholders' Equity - Estimated Fair Value of ESPP Shares (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014	Dec. 28, 2013	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility		52.00%
Risk-free interest rate		1.30%
Expected life		4 years 3 months 18 days
Estimated fair value (in usd per share)		$3.85
Stock-based compensation expense	$7,208	$6,672
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$14.97
Volatility	48.00%		55.00%
Risk-free interest rate			0.42%
Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility	53.00%	51.00%
Risk-free interest rate	0.13%	0.11%
Expected life	6 months	6 months
Estimated fair value (in usd per share)	$5.15	$2.57
Stock-based compensation expense	$1,051	$791
Minimum | Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$18.08		6.27	$6.59
Volatility				49.00%
Risk-free interest rate				0.66%
Maximum | Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Per Share, granted (in usd per share)	$19.29		7.06	$7.60
Volatility				50.00%
Risk-free interest rate				0.71%

Stockholders_Equity_Summary_of3

Stockholders' Equity - Summary of Effects of Stock-Based Compensation on Company's Balance Sheets (Details) (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Stock-Based Compensation Effects in Inventory
Effects Of Stock Based Compensation [Line Items]
Effects Of Stock Based Compensation	$3,083	$3,088
Stock-Based Compensation Effects in Deferred Inventory Cost
Effects Of Stock Based Compensation [Line Items]
Effects Of Stock Based Compensation	13	13
Stock-Based Compensation Effects in Fixed Assets
Effects Of Stock Based Compensation [Line Items]
Effects Of Stock Based Compensation	$113	$119

Stockholders_Equity_Summary_of4

Stockholders' Equity - Summary of Effects of Stock-Based Compensation on Company's Statements of Operations (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015		Mar. 29, 2014
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes	$6,447		$5,840
Cost of revenue - amortization from balance sheet	761	[1]	832	[1]
Allocated Share-based Compensation Expense	7,208		6,672
Cost of revenue
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes	482		452
Research and development
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes	2,578		2,138
Sales and marketing
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes	1,721		1,720
General and administration
Effects Of Stock Based Compensation [Line Items]
Stock-based compensation effects included in net income (loss) before income taxes	$1,666		$1,530
[1]	Stock-based compensation expense deferred to inventory and deferred inventory costs in prior periods and recognized in the current period.

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Income Tax Disclosure [Abstract]
Provision for income taxes	$616	$248
Pre-tax income (loss)	$12,982	($4,126)

Segment_Information_Revenue_an

Segment Information - Revenue and Long-Lived Assets by Geographic Region (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
	segment
Segment Reporting [Abstract]
Number of Reportable Segments	1
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$186,862	$142,815
Operating Segments | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	127,003	110,691
Operating Segments | Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	7,086	3,536
Operating Segments | Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	134,089	114,227
Operating Segments | Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	45,879	25,613
Operating Segments | Asia Pacific and Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$6,894	$2,975

Segment_Information_Property_P

Segment Information - Property, Plant and Equipment, Net (Details) (USD $)	Mar. 28, 2015	Dec. 27, 2014
In Thousands, unless otherwise specified
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	$82,661	$81,566
Operating Segments | United States
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	79,898	79,025
Operating Segments | Other Americas
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	154	196
Operating Segments | Europe, Middle East and Africa
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	797	1,477
Operating Segments | Asia Pacific and Japan
Geographic Information For Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	$1,812	$868

Guarantees_Additional_Informat

Guarantees - Additional Information (Details)	3 Months Ended
	Mar. 28, 2015
Minimum
Guarantor Obligations [Line Items]
Product warranty period	1 year
Maximum
Guarantor Obligations [Line Items]
Product warranty period	5 years

Guarantees_Activity_Related_to

Guarantees - Activity Related to Product Warranty (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 28, 2015	Mar. 29, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$27,040	$22,908
Charges to operations	5,348	5,561
Utilization	-1,818	-3,242
Change in estimate	-5,031	1,158
Balance at the end of the period	$25,539	$26,385

Subsequent_Event_Details

Subsequent Event (Details)	Mar. 28, 2015		Dec. 27, 2014		Apr. 23, 2015	Apr. 08, 2015	Apr. 08, 2015	Apr. 09, 2015	Apr. 09, 2015	Mar. 31, 2015
	USD ($)		USD ($)		Transmode [Member]	Transmode [Member]	Transmode [Member]	Transmode [Member]	Transmode [Member]	Transmode [Member]
					Subsequent Event	Subsequent Event	Subsequent Event	Subsequent Event	Subsequent Event	Subsequent Event
					SEK	USD ($)	SEK	USD ($)	SEK
Subsequent Event [Line Items]
Percent of the Transmode shares exchanged						73.80%	73.80%
Shares of Infinera’s common stock per Transmode share						0.6376	0.6376
Percent of the Transmode shares exchanged in cash						26.20%	26.20%
Transmode shares exchanged with cash (in sek per share)							107.05
Business Combination, Acquiree Dividend Per Share					1.95
Total shares issued for business acquisition						13,037,699	13,037,699
Percent of Infinera stock outstanding						10.10%	10.10%
Former Transmode shareholders percentage stake in Infinera						9.20%	9.20%
Fully diluted combined company shareholders stake						8.70%	8.70%
Cash portion of offer						$88,900,000
Business Combination, Acquiree Common Stock, Shares, Outstanding										27,709,236
Business Combination, Acquiree Treasury Stock, Shares										79,440
Common stock, shares outstanding (in shares)	129,093,644		126,160,000
Forward contract notional amount	$25,043,000	[1]	$38,359,000	[1]				$95,300,000	831,000,000
Currency exposure exchange rate hedge								8.7402	8.7402
[1]	Represents the face amounts of forward contracts that were outstanding as of the period noted.