Infinera (INFN) 10-Q 30 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 29, 2014	Apr. 23, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	29-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'INFN	'
Entity Registrant Name	'INFINERA CORP	'
Entity Central Index Key	'0001138639	'
Current Fiscal Year End Date	'--12-27	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	122,490,560

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$85,249	$124,330
Short-term investments	226,705	172,660
Accounts receivable, net of allowance for doubtful accounts of $41 in 2014 and $43 in 2013	107,405	100,643
Inventory	126,465	123,685
Prepaid expenses and other current assets	20,537	17,752
Total current assets	566,361	539,070
Property, plant and equipment, net	78,801	79,668
Long-term investments	32,756	64,419
Cost-method investment	9,000	9,000
Long-term restricted cash	4,392	3,904
Other non-current assets	5,776	4,865
Total assets	697,086	700,926
Current liabilities:	'	'
Accounts payable	37,843	39,843
Accrued expenses	20,244	22,431
Accrued compensation and related benefits	21,377	33,899
Accrued warranty	14,351	12,374
Deferred revenue	31,496	32,402
Total current liabilities	125,311	140,949
Long-term debt, net	111,024	109,164
Accrued warranty, non-current	12,034	10,534
Deferred revenue, non-current	4,886	4,888
Other long-term liabilities	17,563	17,581
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
Common stock, $0.001 par value Authorized shares – 500,000 as of March 29, 2014 and December 28, 2013 Issued and outstanding shares – 122,485 as of March 29, 2014 and 119,887 as of December 28, 2013	123	120
Additional paid-in capital	1,038,216	1,025,661
Accumulated other comprehensive loss	-3,212	-3,486
Accumulated deficit	-608,859	-604,485
Total stockholders’ equity	426,268	417,810
Total liabilities and stockholders’ equity	$697,086	$700,926

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Net of allowance for doubtful accounts	$41	$43
Preferred stock, par value (USD per share)	$0.00	$0.00
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (USD per share)	$0.00	$0.00
Common stock, authorized shares	500,000,000	500,000,000
Common stock, shares issued	122,485,000	119,887,000
Common stock, shares outstanding	122,485,000	119,887,000

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Revenue:	'	'
Product	$124,242	$108,343
Services	18,573	16,282
Total revenue	142,815	124,625
Cost of revenue:	'	'
Cost of product	78,438	75,447
Cost of services	5,971	6,476
Total cost of revenue	84,409	81,923
Gross profit	58,406	42,702
Operating expenses:	'	'
Research and development	29,346	29,726
Sales and marketing	17,862	18,046
General and administrative	12,254	9,872
Total operating expenses	59,462	57,644
Loss from operations	-1,056	-14,942
Other income (expense), net:	'	'
Interest income	336	197
Interest expense	-2,677	0
Other gain (loss), net:	-729	-203
Total other income (expense), net	-3,070	-6
Loss before income taxes	-4,126	-14,948
Provision for income taxes	248	331
Net loss	($4,374)	($15,279)
Net loss per common share	'	'
Basic (USD per share)	($0.04)	($0.13)
Diluted (USD per share)	($0.04)	($0.13)
Weighted average shares used in computing net loss per common share	'	'
Basic (in shares)	121,352	114,308
Diluted (in shares)	121,352	114,308

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net loss	($4,374)	($15,279)
Other comprehensive loss:	'	'
Reclassification of realized gain on auction rate securities	0	-166
Unrealized gain (loss) on all other available-for-sale investments	50	-9
Foreign currency translation adjustment	244	-117
Tax related to available-for-sale investment	-20	0
Net change in accumulated other comprehensive loss	274	-292
Comprehensive loss	($4,100)	($15,571)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Cash Flows from Operating Activities:	'	'
Net loss	($4,374)	($15,279)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	6,314	6,334
(Recovery of) provision for other receivables	0	-88
Amortization of debt discount and issuance costs	2,020	0
Amortization of premium on investments	828	314
Stock-based compensation expense	6,672	7,975
Other gain	-20	-243
Changes in assets and liabilities:	'	'
Accounts receivable	-6,762	-5,094
Inventory	-3,354	-5,041
Prepaid expenses and other assets	-3,797	-361
Accounts payable	-2,080	-8,045
Accrued liabilities and other expenses	-13,448	-6,301
Deferred revenue	-909	4,340
Accrued Warranty	3,477	190
Net cash used in operating activities	-15,433	-21,299
Cash Flows from Investing Activities:	'	'
Purchase of available-for-sale investments	-80,223	-20,023
Proceeds from sale of available-for-sale investments	0	2,850
Proceeds from maturities and calls of investments	57,063	33,835
Purchase of property and equipment	-5,608	-4,936
Change in restricted cash	-479	44
Net cash provided by (used in) investing activities	-29,247	11,770
Cash Flows from Financing Activities:	'	'
Proceeds from issuance of common stock	7,054	5,560
Minimum tax withholding paid on behalf of employees for net share settlement	-1,619	-1,493
Net cash provided by financing activities	5,435	4,067
Effect of exchange rate changes on cash	164	-206
Net change in cash and cash equivalents	-39,081	-5,668
Cash and cash equivalents at beginning of period	124,330	104,666
Cash and cash equivalents at end of period	85,249	98,998
Supplemental disclosures of cash flow information:	'	'
Cash paid for income taxes, net of refunds	303	210
Supplemental schedule of non-cash financing activities:	'	'
Transfer of inventory to fixed assets	$603	$1,522

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 29, 2014
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 28, 2013.
	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, allowances for sales returns, allowances for doubtful accounts, accrued warranty, fair value measurement of the liability component of the convertible senior notes, fair value measurement of cash equivalents, investments and derivative instruments, other-than-temporary impairments and accounting for income taxes. 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 28, 2013.
	There have been no material changes in the Company’s significant accounting policies for the three months ended March 29, 2014 as compared to those disclosed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 28, 2013.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 29, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board issued Accounting Standards Update 2013-11, "Income Taxes - Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carry Forward, a Similar Tax Loss, or a Tax Credit Carry Forwards Exists" (“ASU 2013-11”). ASU 2013-11 requires entities to present the unrecognized tax benefits in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as follows. To the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. ASU 2013-11 is effective for annual and interim periods for fiscal years beginning on or after December 15, 2013. The Company's adoption of ASU 2013-11 during the first quarter of 2014 had no impact on the Company’s financial position, results of operations or cash flow.

Fair_Value_Measurements_and_Ot

Fair Value Measurements and Other-Than-Temporary Impairments	3 Months Ended
	Mar. 29, 2014
Text Block [Abstract]	'
Fair Value Measurements and Other-Than-Temporary Impairments	'
	Fair Value Measurements and Other-Than-Temporary Impairments
	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, derivative instruments 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.
	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.
	As of March 29, 2014, none of the Company’s existing securities were classified as Level 3 securities.
	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 29, 2014															As of December 28, 2013
		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	$	33,005			$	—		$	—			$	33,005			$	51,749			$	—	$	—	$	51,749
	Certificates of deposit	—				3,600			—				3,600				—				3,840		—		3,840
	Commercial paper	—				77,640			—				77,640				—				85,860		—		85,860
	Corporate bonds	—				178,908			—				178,908				—				150,595		—		150,595
	U.S. treasuries	4,805				—			—				4,805				4,804				—		—		4,804
	Foreign currency exchange forward contracts	—				—			—				—				—				29		—		29
	Total assets	$	37,810			$	260,148		$	—			$	297,958			$	56,553			$	240,324	$	—	$	296,877
	Liabilities
	Foreign currency exchange forward contracts	$	—			$	80		$	—			$	80			$	—			$	26	$	—	$	26
	During the first quarter of 2014, there were no transfers of assets or liabilities between Level 1 and Level 2.
	Investments at fair value were as follows (in thousands):
		29-Mar-14
		Adjusted				Gross			Gross				Fair Value
		Amortized				Unrealized			Unrealized
		Cost				Gains			Losses
	Money market funds	$	33,005			$	—		$	—			$	33,005
	Certificates of deposit	3,600				—			—				3,600
	Commercial paper	77,645				3			(8		)		77,640
	Corporate bonds	178,981				44			(117		)		178,908
	U.S. treasuries	4,801				4			—				4,805
	Total available-for-sale investments	$	298,032			$	51		$	(125	)		$	297,958
		December 28, 2013
		Adjusted				Gross			Gross				Fair Value
		Amortized				Unrealized			Unrealized
		Cost				Gains			Losses
	Money market funds	$	51,749			$	—		$	—			$	51,749
	Certificates of deposit	3,840				—			—				3,840
	Commercial paper	85,870				2			(12		)		85,860
	Corporate bonds	150,711				27			(143		)		150,595
	U.S. treasuries	4,802				2			—				4,804
	Total available-for-sale investments	$	296,972			$	31		$	(155	)		$	296,848
	As of March 29, 2014, the Company’s available-for-sale investments in certificates of deposit, commercial paper, corporate bonds, and U.S. treasuries have a contractual maturity term of no more than 16 months. Proceeds from sales and maturities of available-for-sale investments were $57.1 million for the first quarter of 2014. The Company had no net realized gains (losses) on short-term and long-term investments for the first quarter of 2014. The specific identification method is used to account for gains and losses on available-for-sale investments.
	As of March 29, 2014 and December 28, 2013, the Company held $46.8 million and $64.6 million of cash in banks, respectively.
	Other-Than-Temporary Impairments
	As a result of the Company’s disposal of $3.1 million auction rate securities (par value) during the three months ended March 30, 2013, it recorded an approximately $0.2 million gain, which was recognized as Other gain (loss) in the Company’s condensed consolidated statements of operations.
	A roll-forward of amortized cost, cumulative other-than-temporary impairments ("OTTI") recognized in earnings and Accumulated other comprehensive loss is as follows (in thousands):
		Amortized				Cumulative				Unrealized				OTTI Loss in				Accumulated
		Cost				OTTI in				Gain				Accumulated				Other
						Earnings								Other				Comprehensive
														Comprehensive				Income (Loss)
										Loss
Balance at December 29, 2012	$	2,707			$	(394	)		$	784			$	(618	)		$	166
Call on investments	(87		)		13				(25		)		20				(5		)
Investments sold	(2,620		)		381				(759		)		598				(161		)
Balance at March 30, 2013	$	—			$	—			$	—			$	—			$	—

Costmethod_Investment

Cost-method Investment	3 Months Ended
	Mar. 29, 2014
Investments, All Other Investments [Abstract]	'
Cost-method Investment	'
	Cost-method Investment
	As of March 29, 2014, the Company’s investment in a privately-held company was $9.0 million. 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. The Company’s cost-method investment is carried at historical cost in its condensed consolidated financial statements and measured at fair value on a nonrecurring basis. 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. The Company regularly evaluates the carrying value of this cost-method investment for impairment. As of March 29, 2014, no event had occurred that would adversely affect the carrying value of this investment, therefore, the fair value of the cost-method investment is not estimated. The Company did not record any impairment charges for this cost-method investment during the three months ended March 29, 2014 and March 30, 2013.

Derivative_Instruments

Derivative Instruments	3 Months Ended
	Mar. 29, 2014
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 first quarter of 2014 were denominated in euros and British pound, 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 29, 2014, 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 first quarter of 2014, the before-tax effect of foreign currency exchange forward contracts not designated as hedging instruments was a loss of $0.4 million included in Other gain (loss), net in the condensed consolidated statements of operations.
	The fair value of derivative instruments not designated as hedging instruments in the Company’s condensed consolidated balance sheets was as follows (in thousands):
		As of March 29, 2014							As of December 28, 2013
		Gross		Prepaid Expenses and Other Assets		Other			Gross		Prepaid Expenses and Other Assets		Other
		Notional(1)				Accrued			Notional(1)				Accrued
						Liabilities							Liabilities
	Foreign currency exchange forward contracts
	Related to euro denominated receivables	$	20,609	—		$	(72	)	$	16,867	27		$	—
	Related to British pound denominated receivables	912		—		(3		)	—		—		(26		)
	Related to restricted cash	1,392		—		(5		)	1,391		2		—
		$	22,913	$	—	$	(80	)	$	18,258	$	29	$	(26	)
	_________________
	(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. 29, 2014
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):
		29-Mar-14			28-Dec-13
	Inventory:
	Raw materials	$	13,199		$	14,311
	Work in process	47,746			49,172
	Finished goods (1)	65,520			60,202
	Total inventory	$	126,465		$	123,685
	Property, plant and equipment, net:
	Computer hardware	$	10,053		$	9,692
	Computer software(2)	17,236			16,988
	Laboratory and manufacturing equipment	151,132			146,834
	Furniture and fixtures	1,346			1,347
	Leasehold improvements	36,006			35,913
	Construction in progress	9,218			8,950
	Subtotal	$	224,991		$	219,724
	Less accumulated depreciation and amortization	(146,190		)	(140,056		)
	Total property, plant and equipment, net	$	78,801		$	79,668
	Accrued expenses:
	Loss contingency related to non-cancelable purchase commitments	$	3,454		$	5,120
	Professional and other consulting fees	1,534			1,411
	Taxes payable	2,693			2,372
	Royalties	1,503			1,540
	Accrued rebate and customer prepay liability	644			3,807
	Accrued interest on convertible senior notes	875			219
	Other accrued expenses	9,541			7,962
	Total accrued expenses	$	20,244		$	22,431
	_________________
	(1)	Included in finished goods inventory at March 29, 2014 and December 28, 2013 were $8.0 million and $9.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
	(2)	Included in computer software at March 29, 2014 and December 28, 2013 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 29, 2014 and December 28, 2013 were $6.0 million and $6.3 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 outstanding standby letters of credit (in thousands):
		March 29,			December 28,
		2014			2013
	Value added tax license	$	1,463		$	1,430
	Customer proposal guarantee	1,876			1,446
	Property leases	699			699
	Total standby letters of credit	$	4,038		$	3,575

Comprehensive_Loss

Comprehensive Loss	3 Months Ended
	Mar. 29, 2014
Equity [Abstract]	'
Comprehensive Loss	'
	Comprehensive Loss
	Other comprehensive loss includes certain changes in equity that are excluded from net loss. The following table sets forth the changes in accumulated other comprehensive loss by component for the first quarter of 2014 (in thousands):
		Unrealized Gain			Foreign			Accumulated			Total
		on Other			Currency Translation			Tax Effect
		Available-for-Sale
		Securities
	Balance at December 28, 2013	$	(124	)	$	(2,602	)	$	(760	)	$	(3,486	)
	Net current-period other comprehensive loss	50			244			(20		)	274
	Balance at March 29, 2014	$	(74	)	$	(2,358	)	$	(780	)	$	(3,212	)

Basic_and_Diluted_Net_Income_L

Basic and Diluted Net Income (Loss) Per Common Share	3 Months Ended
	Mar. 29, 2014
Earnings Per Share [Abstract]	'
Basic and Diluted Net Loss Per Common Share	'
	Basic and Diluted Net Loss Per Common Share
	Basic net loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per common share is computed using net 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 vesting of outstanding restricted stock units (“RSUs”) and performance stock units (“PSUs”), assumed conversion of 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 when they become contingently issuable and excludes such shares when they are not contingently issuable. In net loss periods, these potentially diluted common shares are anti-dilutive and therefore, excluded from the diluted net loss calculation.
	The following table sets forth the computation of loss per common share – basic and diluted (in thousands, except per share amounts):
		Three Months Ended
		29-Mar-14				30-Mar-13
	Net loss	$	(4,374	)		$	(15,279	)
	Weighted average common shares outstanding - basic and diluted	121,352				114,308
	Net loss per common share - basic and diluted	$	(0.04	)		$	(0.13	)
	The Company had the following equity awards outstanding that could potentially dilute basic net loss per common share in the future, but were excluded from the computation of diluted loss per common share in the periods presented as their effect would have been anti-dilutive under the treasury stock method (in thousands):
		Three Months Ended
		29-Mar-14			30-Mar-13
	Stock options	6,135			8,591
	Restricted stock units	5,386			5,407
	Performance stock units	763			553
	Employee stock purchase plan shares	431			601
	Total	12,715			15,152
	In the first quarter of 2014, the Company excluded the potential shares issued upon early conversion of the convertible senior notes in the calculation of diluted earnings per share because the market price was below the conversion price. In the future, the Company would include these dilutive effects of the convertible senior notes in the calculation of diluted net income per common share if the market price is above the conversion price. Upon conversion of the convertible senior 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.

Convertible_Senior_Notes

Convertible Senior Notes	3 Months Ended
	Mar. 29, 2014
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 and the conversion value of the Notes being converted and 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 ending 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 will, 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 amounts recorded in connection with the issuance of the Notes consisted of the following (in thousands):
		Other Non-			Long-term			Additional Paid-
		Current			Debt			in Capital
		Assets
	Principal amount	$	—		$	150,000		$	—
	Debt discount	—			(45,000		)	—
	Equity component	—			—			45,000
	Debt issuance cost	3,872			—			(1,659		)
	Initial transaction amounts	$	3,872		$	105,000		$	43,341
	Amortization of debt issuance cost	(518		)	—			—
	Amortization of debt discount	—			6,024			—
	Net carrying amount at March 29, 2014	$	3,354		$	111,024		$	43,341
	In accounting for the issuance of the Notes, the Company separated the Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount (“debt discount”) is amortized to interest expense over the term of the Notes. The remaining debt discount amount to be amortized over the remaining five years until maturity of the Notes was $39.0 million as of March 29, 2014.
	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
		29-Mar-14
	Contractual interest expense	$	657
	Amortization of debt issuance costs	160
	Amortization of debt discount	1,860
	Total interest expense	$	2,677
	The effective interest rate of the liability component was 1.75%. The excess of the principal amount of the liability component over its carrying amount is amortized, using an effective interest rate of 5.12%, to interest expense over the term of the Notes.
	As of March 29, 2014, the fair value of the Notes was $155.4 million. The fair value was determined based on the quoted bid price of the Notes in an over-the-counter market on March 28, 2014. The Notes are classified as Level 2 of the fair value hierarchy. Based on the closing price of the Company’s common stock of $8.76 on March 28, 2014, the if-converted value of the Notes was less than their principal amount.

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 29, 2014
Equity [Abstract]	'
Stockholders' Equity	'
	Stockholders’ Equity
	Stock-based Compensation Plans
	The Company has stock-based compensation plans pursuant to which the Company has granted stock options, RSUs and PSUs. The Company also has an ESPP for all eligible employees. As of March 29, 2014, there were a total of 19.2 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			Weighted-Average			Aggregate
		Options			Exercise			Intrinsic
					Price			Value
					Per Share
	Outstanding at December 28, 2013	6,367			$	7.26		$	17,452
	Options granted	25			$	9.02
	Options exercised	(227	)		$	5.85		$	649
	Options canceled	(30	)		$	10.3
	Outstanding at March 29, 2014	6,135			$	7.3		$	10,841
	Vested and expected to vest as of March 29, 2014	6,130						$	10,835
	Exercisable at March 29, 2014	5,976			$	7.29		$	10,636
		Number of			Weighted-			Aggregate
		Restricted			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 28, 2013	6,583			$	7.72		$	64,443
	RSUs granted	490			$	8.64
	RSUs released	(1,541	)		$	7.91		$	12,981
	RSUs canceled	(146	)		$	7.02
	Outstanding at March 29, 2014	5,386			$	7.77		$	47,181
	Expected to vest at March 29, 2014	5,198						$	45,539
		Number of			Weighted-			Aggregate
		Performance			Average			Intrinsic
		Stock Units			Grant Date			Value
					Fair Value
					Per Share
	Outstanding at December 28, 2013	721			$	7.04		$	7,054
	PSUs granted	338			$	6.62
	PSUs released	(255	)		$	6.36		$	2,097
	PSUs canceled	(41	)		$	7.25
	Outstanding at March 29, 2014	763			$	7.04		$	6,684
	Expected to vest at March 29, 2014	541						$	4,738
	The aggregate intrinsic value of unexercised options, unreleased RSUs and unreleased PSUs is calculated as the difference between the closing price of the Company’s common stock of $8.76 at March 28, 2014 and the exercise prices of the underlying equity awards. The aggregate intrinsic value of the options that have been exercised and RSUs released is calculated as the difference between the fair market value of the common stock at the date of exercise or release and the exercise price of the underlying equity awards.
	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 29, 2014. 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	543			1.7
	RSUs	28,289			2.3
	PSUs	2,759			1.8
	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	29-Mar-14		30-Mar-13
	Volatility	52%		N/A
	Risk-free interest rate	1.30%		N/A
	Expected life	4.3 years		N/A
	Estimated fair value	$3.85		N/A
	Total stock-based compensation expense	$388		$803
	_________________
	N/A	Not applicable because the Company did not grant any options to employees for the periods presented.
	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	29-Mar-14		30-Mar-13
	Volatility	51%		46%
	Risk-free interest rate	0.11%		0.14%
	Expected life	0.5 years		0.5 years
	Estimated fair value	$2.57		$1.87
Total stock-based compensation expense	$791		$708
Restricted Stock Units
During the first quarter of 2014, the Company granted RSUs to employees and members of the Company’s board of directors to receive an aggregate of 0.5 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 29, 2014 and March 30, 2013 was approximately $5.1 million and $6.9 million, respectively.
Performance Stock Units
Pursuant to the Company’s 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 first quarter of 2014, the Company did not release any shares subject to the PSUs upon achievement of the performance goals.
Pursuant to the Company’s 2007 Plan, during fiscal 2013, the Company granted 0.6 million shares 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 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 first quarter of 2014, the Company released 0.3 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
Pursuant to the Company's 2007 Plan, during the first quarter of 2014, the Company granted 0.3 million shares 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 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.
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
	March 29,
	2014
Infinera Volatility	49%
IGN Index Volatility	25%
Risk-free interest rate	0.66%
Correlation with IGN Index	0.6
Estimated fair value	$6.61 - $7.60
Amortization of stock-based compensation related to PSUs in the first quarter of 2014 was approximately $0.4 million. Amortization of stock-based compensation related to PSUs in the first quarter of 2013 was a credit of approximately $0.8 million, including $0.6 million of expense offset by a $1.4 million decrease in fair value for one award classified as a liability award, in accordance with Accounting Standard Codification 718, "Compensation - Stock Compensation."
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):
	29-Mar-14				28-Dec-13
Stock-based compensation effects in inventory	$	3,219			$	3,189
Stock-based compensation effects in deferred inventory cost	$	14			$	15
Stock-based compensation effects in fixed assets	$	139			$	145
	Three Months Ended
	29-Mar-14				30-Mar-13
Stock-based compensation effects included in net loss before income taxes
Cost of revenue	$	452			$	486
Research and development	2,138				3,119
Sales and marketing	1,720				1,999
General and administration	1,530				769
	5,840				6,373
Cost of revenue – amortization from balance sheet (1)	832				1,602
Total stock-based compensation expense	$	6,672			$	7,975
_________________
(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. 29, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Provision for income taxes for the three months ended March 29, 2014 was $0.2 million, or negative 6.0%, on a pre-tax loss of $4.1 million. This compared to a tax provision of $0.3 million, or negative 2.2%, on a pre-tax loss of $14.9 million for the three months ended March 30, 2013. The difference between the Company’s effective tax rates and the federal statutory rate of 35% is primarily attributable to U.S. losses, foreign taxes provided on the income of the Company’s foreign subsidiaries, non-deductible stock-based compensation expense and various discrete items. 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 realization of tax benefits of deferred tax assets is dependent upon future levels of taxable income, of an appropriate character, in the periods the items are scheduled to be deductible or taxable. Based on the available objective evidence, management believes it is more likely than not that the domestic net deferred tax assets will not be realizable. Accordingly, the Company has provided a full valuation allowance against its domestic deferred tax assets, net of deferred tax liabilities, as of March 29, 2014 and December 28, 2013. In determining future taxable income, the Company makes assumptions to forecast federal, state and international operating income, the reversal of taxable temporary differences, and the implementation of any feasible and prudent tax planning strategies. The assumptions require judgment regarding the forecasts of future taxable income and are consistent with the Company’s forecasts used to manage its business. The Company intends to maintain the remaining valuation allowance until sufficient positive evidence exists to support a reversal of, or decrease, in the valuation allowance.

Segment_Information

Segment Information	3 Months Ended
	Mar. 29, 2014
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, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the consolidated unit level. 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
		29-Mar-14		30-Mar-13
	Americas:
	United States	$	110,691	$	79,073
	Other Americas	3,536		718
		114,227		79,791
	Europe, Middle East and Africa	25,613		38,806
	Asia Pacific and Japan	2,975		6,028
	Total revenue	$	142,815	$	124,625
	Property, plant and equipment, net
		March 29,		December 28,
		2014		2013
	United States	$	76,029	$	76,850
	Other Americas	275		319
	Europe, Middle East and Africa	1,027		1,451
	Asia Pacific and Japan	1,470		1,048
	Total property, plant and equipment, net	$	78,801	$	79,668

Guarantees

Guarantees	3 Months Ended
	Mar. 29, 2014
Guarantees [Abstract]	'
Guarantees	'
	Guarantees
	Product Warranties
	Upon delivery of products, the Company provides for the estimated cost to repair or replace products including the related components that may be returned under hardware warranties. In general, hardware warranty periods range from one to five years. 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 or replacement. The Company estimates its hardware warranty obligations based on the Company’s historical experience of known product failure rates, use of materials and labor to repair or replace defective products, and service delivery costs incurred in correcting product failures. In addition, from time to time, specific hardware warranty accruals may be made if unforeseen technical problems arise with specific products. Management periodically assesses the adequacy of the Company’s recorded warranty liabilities and adjusts the amounts as necessary.
	Activity related to product warranty was as follows (in thousands):
		Three Months Ended
		29-Mar-14			30-Mar-13
	Beginning balance	$	22,908		$	16,482
	Charges to operations	5,561			4,168
	Utilization	(3,242		)	(2,083		)
	Change in estimate (1)	1,158			(1,895		)
	Balance at the end of the period	$	26,385		$	16,672
	(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 and the resulting impact of these changes on the Company’s estimate of expected future returns, as well as changes in the estimated cost of replacing failed units with either repaired or new units.

Litigation_and_Contingencies

Litigation and Contingencies	3 Months Ended
	Mar. 29, 2014
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 our 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 14, 2014, the Company filed three motions for summary judgment relating to non-infringement and damages. The court scheduled a hearing on the summary judgment motions for June 9, 2014. The court also scheduled a pretrial conference for July 7, 2014, and the jury trial is set to begin on July 22, 2014.
	Based on the information available at this time, the Company concluded that the likelihood of a loss with respect to this suit is reasonably possible. The Company has further concluded that the range of the reasonably possible loss is an insignificant amount and will not have a material adverse effect on the Company’s business, consolidated financial position, results of operations, or cash flows. Accordingly, the Company accrued an insignificant amount during 2013, which did not 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 nature of the litigation (including the complex and technical nature of patent litigation), the length of time the matter has been pending, the status of the plaintiff as a non-operating entity and the likelihood of the plaintiff accepting the estimated amount. However, the outcome of such legal matters is inherently unpredictable and subject to significant uncertainties.
	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 29, 2014, the Company has not accrued or recorded any such material liabilities.

Recent_Accounting_Pronouncemen1

Recent Accounting Pronouncements Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 29, 2014
Accounting Changes and Error Corrections [Abstract]	'
Income tax	'
	The Company's adoption of ASU 2013-11 during the first quarter of 2014 had no impact on the Company’s financial position, results of operations or cash flow.

Fair_Value_Measurements_and_Ot1

Fair Value Measurements and Other-Than-Temporary Impairments (Tables)	3 Months Ended
	Mar. 29, 2014
Text Block [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 29, 2014														As of December 28, 2013
		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	$	33,005		$	—		$	—			$	33,005			$	51,749			$	—	$	—	$	51,749
	Certificates of deposit	—			3,600			—				3,600				—				3,840		—		3,840
	Commercial paper	—			77,640			—				77,640				—				85,860		—		85,860
	Corporate bonds	—			178,908			—				178,908				—				150,595		—		150,595
	U.S. treasuries	4,805			—			—				4,805				4,804				—		—		4,804
	Foreign currency exchange forward contracts	—			—			—				—				—				29		—		29
	Total assets	$	37,810		$	260,148		$	—			$	297,958			$	56,553			$	240,324	$	—	$	296,877
	Liabilities
	Foreign currency exchange forward contracts	$	—		$	80		$	—			$	80			$	—			$	26	$	—	$	26
Investments at Fair Value	'
	Investments at fair value were as follows (in thousands):
		29-Mar-14
		Adjusted			Gross			Gross				Fair Value
		Amortized			Unrealized			Unrealized
		Cost			Gains			Losses
	Money market funds	$	33,005		$	—		$	—			$	33,005
	Certificates of deposit	3,600			—			—				3,600
	Commercial paper	77,645			3			(8		)		77,640
	Corporate bonds	178,981			44			(117		)		178,908
	U.S. treasuries	4,801			4			—				4,805
	Total available-for-sale investments	$	298,032		$	51		$	(125	)		$	297,958
		December 28, 2013
		Adjusted			Gross			Gross				Fair Value
		Amortized			Unrealized			Unrealized
		Cost			Gains			Losses
	Money market funds	$	51,749		$	—		$	—			$	51,749
	Certificates of deposit	3,840			—			—				3,840
	Commercial paper	85,870			2			(12		)		85,860
	Corporate bonds	150,711			27			(143		)		150,595
	U.S. treasuries	4,802			2			—				4,804
	Total available-for-sale investments	$	296,972		$	31		$	(155	)		$	296,848
Schedule Of Amortized Cost Cumulative Other Than Temporary Impairment Recognized In Earnings And Accumulated Other Comprehensive Loss	'
	A roll-forward of amortized cost, cumulative other-than-temporary impairments ("OTTI") recognized in earnings and Accumulated other comprehensive loss is as follows (in thousands):
		Amortized			Cumulative				Unrealized				OTTI Loss in				Accumulated
		Cost			OTTI in				Gain				Accumulated				Other
					Earnings								Other				Comprehensive
													Comprehensive				Income (Loss)
													Loss
	Balance at December 29, 2012	$	2,707		$	(394	)		$	784			$	(618	)		$	166
	Call on investments	(87		)	13				(25		)		20				(5		)
	Investments sold	(2,620		)	381				(759		)		598				(161		)
	Balance at March 30, 2013	$	—		$	—			$	—			$	—			$	—

Derivative_Instruments_Tables

Derivative Instruments (Tables)	3 Months Ended
	Mar. 29, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Value of Derivative Instruments not Designated as Hedging Instruments	'
	The fair value of derivative instruments not designated as hedging instruments in the Company’s condensed consolidated balance sheets was as follows (in thousands):
		As of March 29, 2014							As of December 28, 2013
		Gross		Prepaid Expenses and Other Assets		Other			Gross		Prepaid Expenses and Other Assets		Other
		Notional(1)				Accrued			Notional(1)				Accrued
						Liabilities							Liabilities
	Foreign currency exchange forward contracts
	Related to euro denominated receivables	$	20,609	—		$	(72	)	$	16,867	27		$	—
	Related to British pound denominated receivables	912		—		(3		)	—		—		(26		)
	Related to restricted cash	1,392		—		(5		)	1,391		2		—
		$	22,913	$	—	$	(80	)	$	18,258	$	29	$	(26	)
	_________________
	(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. 29, 2014
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):
		29-Mar-14			28-Dec-13
	Inventory:
	Raw materials	$	13,199		$	14,311
	Work in process	47,746			49,172
	Finished goods (1)	65,520			60,202
	Total inventory	$	126,465		$	123,685
	Property, plant and equipment, net:
	Computer hardware	$	10,053		$	9,692
	Computer software(2)	17,236			16,988
	Laboratory and manufacturing equipment	151,132			146,834
	Furniture and fixtures	1,346			1,347
	Leasehold improvements	36,006			35,913
	Construction in progress	9,218			8,950
	Subtotal	$	224,991		$	219,724
	Less accumulated depreciation and amortization	(146,190		)	(140,056		)
	Total property, plant and equipment, net	$	78,801		$	79,668
	Accrued expenses:
	Loss contingency related to non-cancelable purchase commitments	$	3,454		$	5,120
	Professional and other consulting fees	1,534			1,411
	Taxes payable	2,693			2,372
	Royalties	1,503			1,540
	Accrued rebate and customer prepay liability	644			3,807
	Accrued interest on convertible senior notes	875			219
	Other accrued expenses	9,541			7,962
	Total accrued expenses	$	20,244		$	22,431
	_________________
	(1)	Included in finished goods inventory at March 29, 2014 and December 28, 2013 were $8.0 million and $9.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
	(2)	Included in computer software at March 29, 2014 and December 28, 2013 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 29, 2014 and December 28, 2013 were $6.0 million and $6.3 million, respectively.
Schedule of Components of Letters of Credit	'
	The following table sets forth the Company's outstanding standby letters of credit (in thousands):
		March 29,			December 28,
		2014			2013
	Value added tax license	$	1,463		$	1,430
	Customer proposal guarantee	1,876			1,446
	Property leases	699			699
	Total standby letters of credit	$	4,038		$	3,575

Comprehensive_Loss_Tables

Comprehensive Loss (Tables)	3 Months Ended
	Mar. 29, 2014
Equity [Abstract]	'
Summary of Changes in Accumulated Other Comprehensive Loss	'
	Other comprehensive loss includes certain changes in equity that are excluded from net loss. The following table sets forth the changes in accumulated other comprehensive loss by component for the first quarter of 2014 (in thousands):
		Unrealized Gain			Foreign			Accumulated			Total
		on Other			Currency Translation			Tax Effect
		Available-for-Sale
		Securities
	Balance at December 28, 2013	$	(124	)	$	(2,602	)	$	(760	)	$	(3,486	)
	Net current-period other comprehensive loss	50			244			(20		)	274
	Balance at March 29, 2014	$	(74	)	$	(2,358	)	$	(780	)	$	(3,212	)

Basic_and_Diluted_Net_Income_L1

Basic and Diluted Net Income (Loss) Per Common Share (Tables)	3 Months Ended
	Mar. 29, 2014
Earnings Per Share [Abstract]	'
Computation of Net Loss Per Common Share Basic and Diluted	'
	The following table sets forth the computation of loss per common share – basic and diluted (in thousands, except per share amounts):
		Three Months Ended
		29-Mar-14				30-Mar-13
	Net loss	$	(4,374	)		$	(15,279	)
	Weighted average common shares outstanding - basic and diluted	121,352				114,308
	Net loss per common share - basic and diluted	$	(0.04	)		$	(0.13	)
Antidilutive Shares Excluded from Computation of Diluted Net Loss Per Share	'
		Three Months Ended
		29-Mar-14			30-Mar-13
	Stock options	6,135			8,591
	Restricted stock units	5,386			5,407
	Performance stock units	763			553
	Employee stock purchase plan shares	431			601
	Total	12,715			15,152

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	3 Months Ended
	Mar. 29, 2014
Debt Disclosure [Abstract]	'
Components of Convertible Senior Notes	'
	The amounts recorded in connection with the issuance of the Notes consisted of the following (in thousands):
		Other Non-			Long-term			Additional Paid-
		Current			Debt			in Capital
		Assets
	Principal amount	$	—		$	150,000		$	—
	Debt discount	—			(45,000		)	—
	Equity component	—			—			45,000
	Debt issuance cost	3,872			—			(1,659		)
	Initial transaction amounts	$	3,872		$	105,000		$	43,341
	Amortization of debt issuance cost	(518		)	—			—
	Amortization of debt discount	—			6,024			—
	Net carrying amount at March 29, 2014	$	3,354		$	111,024		$	43,341
Interest Expense Recognized Related to Notes	'
	The following table sets forth total interest expense recognized related to the Notes (in thousands):
		Three Months Ended
		29-Mar-14
	Contractual interest expense	$	657
	Amortization of debt issuance costs	160
	Amortization of debt discount	1,860
	Total interest expense	$	2,677

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 29, 2014
Equity [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			Weighted-Average			Aggregate
		Options			Exercise			Intrinsic
					Price			Value
					Per Share
	Outstanding at December 28, 2013	6,367			$	7.26		$	17,452
	Options granted	25			$	9.02
	Options exercised	(227	)		$	5.85		$	649
	Options canceled	(30	)		$	10.3
	Outstanding at March 29, 2014	6,135			$	7.3		$	10,841
	Vested and expected to vest as of March 29, 2014	6,130						$	10,835
	Exercisable at March 29, 2014	5,976			$	7.29		$	10,636
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 28, 2013	6,583			$	7.72		$	64,443
	RSUs granted	490			$	8.64
	RSUs released	(1,541	)		$	7.91		$	12,981
	RSUs canceled	(146	)		$	7.02
	Outstanding at March 29, 2014	5,386			$	7.77		$	47,181
	Expected to vest at March 29, 2014	5,198						$	45,539
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 28, 2013	721			$	7.04		$	7,054
	PSUs granted	338			$	6.62
	PSUs released	(255	)		$	6.36		$	2,097
	PSUs canceled	(41	)		$	7.25
	Outstanding at March 29, 2014	763			$	7.04		$	6,684
	Expected to vest at March 29, 2014	541						$	4,738
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 29, 2014. 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	543			1.7
	RSUs	28,289			2.3
	PSUs	2,759			1.8
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	29-Mar-14		30-Mar-13
	Volatility	52%		N/A
	Risk-free interest rate	1.30%		N/A
	Expected life	4.3 years		N/A
	Estimated fair value	$3.85		N/A
	Total stock-based compensation expense	$388		$803
	_________________
	N/A	Not applicable because the Company did not grant any options to employees for the periods presented.
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	29-Mar-14		30-Mar-13
	Volatility	51%		46%
	Risk-free interest rate	0.11%		0.14%
	Expected life	0.5 years		0.5 years
	Estimated fair value	$2.57		$1.87
	Total stock-based compensation expense	$791		$708
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	'
	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
		March 29,
		2014
	Infinera Volatility	49%
	IGN Index Volatility	25%
	Risk-free interest rate	0.66%
	Correlation with IGN Index	0.6
	Estimated fair value	$6.61 - $7.60
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):
		29-Mar-14				28-Dec-13
	Stock-based compensation effects in inventory	$	3,219			$	3,189
	Stock-based compensation effects in deferred inventory cost	$	14			$	15
	Stock-based compensation effects in fixed assets	$	139			$	145
		Three Months Ended
		29-Mar-14				30-Mar-13
	Stock-based compensation effects included in net loss before income taxes
	Cost of revenue	$	452			$	486
	Research and development	2,138				3,119
	Sales and marketing	1,720				1,999
	General and administration	1,530				769
		5,840				6,373
	Cost of revenue – amortization from balance sheet (1)	832				1,602
	Total stock-based compensation expense	$	6,672			$	7,975
	_________________
	(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. 29, 2014
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
		29-Mar-14		30-Mar-13
	Americas:
	United States	$	110,691	$	79,073
	Other Americas	3,536		718
		114,227		79,791
	Europe, Middle East and Africa	25,613		38,806
	Asia Pacific and Japan	2,975		6,028
	Total revenue	$	142,815	$	124,625
Property, Plant and Equipment, Net	'
	Property, plant and equipment, net
		March 29,		December 28,
		2014		2013
	United States	$	76,029	$	76,850
	Other Americas	275		319
	Europe, Middle East and Africa	1,027		1,451
	Asia Pacific and Japan	1,470		1,048
	Total property, plant and equipment, net	$	78,801	$	79,668

Guarantees_Tables

Guarantees (Tables)	3 Months Ended
	Mar. 29, 2014
Guarantees [Abstract]	'
Activity Related to Product Warranty	'
	Activity related to product warranty was as follows (in thousands):
		Three Months Ended
		29-Mar-14			30-Mar-13
	Beginning balance	$	22,908		$	16,482
	Charges to operations	5,561			4,168
	Utilization	(3,242		)	(2,083		)
	Change in estimate (1)	1,158			(1,895		)
	Balance at the end of the period	$	26,385		$	16,672
	(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 and the resulting impact of these changes on the Company’s estimate of expected future returns, as well as changes in the estimated cost of replacing failed units with either repaired or new units.

Fair_Value_Measurements_and_Ot2

Fair Value Measurements and Other-Than-Temporary Impairments - Additional Information (Details) (USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013	Dec. 28, 2013
Receivables [Abstract]	'	'	'
Available-for-sale investments	'16 months	'	'
Proceeds from sales, maturities and calls of available-for-sale investments	$57,100,000	'	'
Realized gains on these calls	0	200,000	'
Cash	46,800,000	'	64,600,000
Disposal of auction rate securities par value	'	$3,100,000	'

Fair_Value_Measurements_and_Ot3

Fair Value Measurements and Other-Than-Temporary Impairments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Assets	'	'
Total Assets	$297,958	$296,877
Money Market Funds [Member]	'	'
Assets	'	'
Total Assets	33,005	51,749
Certificates of Deposit [Member]	'	'
Assets	'	'
Total Assets	3,600	3,840
Commercial Paper [Member]	'	'
Assets	'	'
Total Assets	77,640	85,860
Corporate Bonds [Member]	'	'
Assets	'	'
Total Assets	178,908	150,595
U.S. Treasuries [Member]	'	'
Assets	'	'
Total Assets	4,805	4,804
Foreign Currency Exchange Forward Contracts [Member]	'	'
Assets	'	'
Total Assets	0	29
Liabilities	'	'
Total Liabilities	80	26
Level 1 [Member]	'	'
Assets	'	'
Total Assets	37,810	56,553
Level 1 [Member] | Money Market Funds [Member]	'	'
Assets	'	'
Total Assets	33,005	51,749
Level 1 [Member] | Certificates of Deposit [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 1 [Member] | Commercial Paper [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 1 [Member] | Corporate Bonds [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 1 [Member] | U.S. Treasuries [Member]	'	'
Assets	'	'
Total Assets	4,805	4,804
Level 1 [Member] | Foreign Currency Exchange Forward Contracts [Member]	'	'
Assets	'	'
Total Assets	0	0
Liabilities	'	'
Total Liabilities	0	0
Level 2 [Member]	'	'
Assets	'	'
Total Assets	260,148	240,324
Level 2 [Member] | Money Market Funds [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 2 [Member] | Certificates of Deposit [Member]	'	'
Assets	'	'
Total Assets	3,600	3,840
Level 2 [Member] | Commercial Paper [Member]	'	'
Assets	'	'
Total Assets	77,640	85,860
Level 2 [Member] | Corporate Bonds [Member]	'	'
Assets	'	'
Total Assets	178,908	150,595
Level 2 [Member] | U.S. Treasuries [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 2 [Member] | Foreign Currency Exchange Forward Contracts [Member]	'	'
Assets	'	'
Total Assets	0	29
Liabilities	'	'
Total Liabilities	80	26
Level 3 [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | Money Market Funds [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | Certificates of Deposit [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | Commercial Paper [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | Corporate Bonds [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | U.S. Treasuries [Member]	'	'
Assets	'	'
Total Assets	0	0
Level 3 [Member] | Foreign Currency Exchange Forward Contracts [Member]	'	'
Assets	'	'
Total Assets	0	0
Liabilities	'	'
Total Liabilities	$0	$0

Fair_Value_Measurements_and_Ot4

Fair Value Measurements and Other-Than-Temporary Impairments - Reconciliation of All Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Fair Value Disclosures [Abstract]	'	'
Realized gains on these calls	$0	$200,000

Fair_Value_Measurements_and_Ot5

Fair Value Measurements and Other-Than-Temporary Impairments - Investments at Fair Value (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	$298,032	$296,972
Gross Unrealized Gains	51	31
Gross Unrealized Losses	-125	-155
Fair Value	297,958	296,848
Money Market Funds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	33,005	51,749
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	33,005	51,749
Certificates of Deposit [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	3,600	3,840
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	3,600	3,840
Commercial Paper [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	77,645	85,870
Gross Unrealized Gains	3	2
Gross Unrealized Losses	-8	-12
Fair Value	77,640	85,860
Corporate Bonds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	178,981	150,711
Gross Unrealized Gains	44	27
Gross Unrealized Losses	-117	-143
Fair Value	178,908	150,595
U.S. Treasuries [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Adjusted Amortized Cost	4,801	4,802
Gross Unrealized Gains	4	2
Gross Unrealized Losses	0	0
Fair Value	$4,805	$4,804

Fair_Value_Measurements_and_Ot6

Fair Value Measurements and Other-Than-Temporary Impairments - Roll-Forward of Amortized Cost, Cumulative OTTI Recognized in Earnings and Accumulated Other Comprehensive Loss (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013	Mar. 30, 2013
In Thousands, unless otherwise specified			OTTI Recognized in Earnings and Accumulated Other Comprehensive Loss [Member]
Amortized Cost	'	'	'
Amortized Cost, Beginning balance	$298,032	$296,972	$2,707
Amortized Cost, Call on investments	'	'	-87
Amortized Cost, Investments sold	'	'	-2,620
Amortized Cost, Ending balance	298,032	296,972	0
Cumulative OTTI in Earnings	'	'	'
Cumulative OTTI in Earnings, Beginning balance	'	'	-394
Cumulative OTTI in Earnings, Call on investments	'	'	-13
Cumulative OTTI in Earnings, Investments sold	'	'	-381
Cumulative OTTI in Earnings, Ending balance	'	'	0
Unrealized Gain	'	'	'
Unrealized Gain, Beginning balance	'	'	784
Unrealized Gain, Call on investments	'	'	-25
Unrealized Gain (Loss) on Investments	'	'	-759
Unrealized Gain, Ending balance	'	'	0
OTTI Loss in Accumulated Other Comprehensive Loss	'	'	'
OTTI Loss in Accumulated Other Comprehensive Loss, Beginning balance	'	'	-618
OTTI Loss in Accumulated Other Comprehensive Loss, Call on investments	'	'	-20
OTTI Loss in Accumulated Other Comprehensive Loss, Investments sold	'	'	-598
OTTI Loss in Accumulated Other Comprehensive Loss, Ending balance	'	'	0
Accumulated Other Comprehensive Income (Loss)	'	'	'
Accumulated Other Comprehensive Income (Loss), Beginning balance	'	'	166
Accumulated Other Comprehensive Income (Loss), Call on investments	'	'	-5
Accumulated Other Comprehensive Income (Loss), Investments sold	'	'	-161
Accumulated Other Comprehensive Income (Loss), Ending balance	'	'	$0

Costmethod_Investment_Addition

Cost-method Investment - Additional Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Statement of Financial Position [Abstract]	'	'
Cost of company investment	$9,000	$9,000
Less than percent of voting securities	20.00%	'

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 29, 2014
Investments, Debt and Equity Securities [Abstract]	'
Euro denominated forward contracts maturity period	'35 days
British pound denominated receivables and typically maturities period	'35 days
Before-tax effect of foreign currency exchange forward contracts not designated as hedging instruments, gain (loss)	$0.40

Derivative_Instruments_Fair_Va

Derivative Instruments - Fair Value of Derivative Instruments Not Designated as Hedging Activities (Details) (USD $)	Mar. 29, 2014		Dec. 28, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'		'
Gross Notional	$22,913	[1]	$18,258	[1]
Prepaid Expenses and Other Assets	20,537		17,752
Other Accrued Liabilities	-80		-26
Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Prepaid Expenses and Other Assets	0		29
Designated as Hedging Instrument [Member] | Euro Denominated Exchange Forward Contracts Receivables [Member]	'		'
Derivative [Line Items]	'		'
Gross Notional	20,609	[1]	16,867	[1]
Prepaid Expenses and Other Assets	0		27
Other Accrued Liabilities	-72		0
Designated as Hedging Instrument [Member] | GBP Denominated Exchange Forward Contracts Receivables [Member]	'		'
Derivative [Line Items]	'		'
Gross Notional	912	[1]	0	[1]
Prepaid Expenses and Other Assets	0		0
Other Accrued Liabilities	-3		-26
Designated as Hedging Instrument [Member] | Foreign Currency Exchange Restricted Cash Forward Contracts [Member]	'		'
Derivative [Line Items]	'		'
Gross Notional	1,392	[1]	1,391	[1]
Prepaid Expenses and Other Assets	0		2
Other Accrued Liabilities	($5)		$0
[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. 29, 2014		Dec. 28, 2013
In Thousands, unless otherwise specified
Inventory:	'		'
Raw materials	$13,199		$14,311
Work in process	47,746		49,172
Finished goods	65,520	[1]	60,202	[1]
Total	126,465		123,685
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	224,991		219,724
Less accumulated depreciation and amortization	-146,190		-140,056
Total	78,801		79,668
Accrued expenses:	'		'
Loss contingency related to non-cancelable purchase commitments	3,454		5,120
Professional and other consulting fees	1,534		1,411
Taxes payable	2,693		2,372
Royalties	1,503		1,540
Accrued rebate and customer prepay liability	644		3,807
Accrued interest on convertible senior notes	875		219
Other accrued expenses	9,541		7,962
Total	20,244		22,431
Computer Hardware [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	10,053		9,692
Computer Software [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	17,236	[2]	16,988	[2]
Laboratory and Manufacturing Equipment [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	151,132		146,834
Furniture and Fixtures [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	1,346		1,347
Leasehold Improvements [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	36,006		35,913
Construction in Progress [Member]	'		'
Property, plant and equipment, net:	'		'
Property, plant and equipment, gross	$9,218		$8,950
[1]	Included in finished goods inventory at March 29, 2014 and December 28, 2013 were $8.0 million and $9.2 million, respectively, of inventory at customer locations for which product acceptance had not occurred.
[2]	Included in computer software at March 29, 2014 and December 28, 2013 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 29, 2014 and December 28, 2013 were $6.0 million and $6.3 million, respectively.

Balance_Sheet_Details_Details_

Balance Sheet Details - Details of Selected Balance Sheet Items (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	$224,991,000	$219,724,000
Property, plant and equipment, net	78,801,000	79,668,000
Customer Locations [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Inventory awaiting customer acceptance	8,000,000	9,200,000
Enterprise Resource Planning Systems [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	7,900,000	7,900,000
Property, plant and equipment, net	$6,000,000	$6,300,000

Balance_Sheet_Details_Letters_

Balance Sheet Details - Letters of Credit (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]	'	'
Value added tax license	$1,463	$1,430
Customer proposal guarantee	1,876	1,446
Property leases	699	699
Letters of credit outstanding	$4,038	$3,575

Comprehensive_Loss_Summary_of_

Comprehensive Loss - Summary of Changes in Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'	'
Beginning balance	($3,486)	'
Net change in accumulated other comprehensive loss	274	-292
Ending balance	-3,212	'
Unrealized Gain on Other Available-for-Sale Securities [Member]	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'	'
Beginning balance	-124	'
Net change in accumulated other comprehensive loss	50	'
Ending balance	-74	'
Foreign Currency Translation [Member]	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'	'
Beginning balance	-2,602	'
Net change in accumulated other comprehensive loss	244	'
Ending balance	-2,358	'
Accumulated Tax Effect [Member]	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]	'	'
Beginning balance	-760	'
Net change in accumulated other comprehensive loss	-20	'
Ending balance	($780)	'

Basic_and_Diluted_Net_Income_L2

Basic and Diluted Net Income (Loss) Per Common Share 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. 29, 2014	Mar. 30, 2013
Earnings Per Share [Abstract]	'	'
Net loss	($4,374)	($15,279)
Weighted average common shares outstanding - basic and diluted	121,352	114,308
Earnings Per Share, Basic and Diluted	($0.04)	($0.13)

Basic_and_Diluted_Net_Income_L3

Basic and Diluted Net Income (Loss) Per Common Share 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. 29, 2014	Mar. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	12,715	15,152
Stock Options [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	6,135	8,591
RSUs [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	5,386	5,407
PSUs [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	763	553
ESPP [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	431	601

Convertible_Senior_Notes_Addit

Convertible Senior Notes - Additional Information (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 29, 2014	Dec. 28, 2013	30-May-13
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Debt instrument interest percentage	1.75%	'	'
Initial conversion rate per $1,000 principal amount of Notes	0.0794834	'	'
Initial conversion price	$12.58	'	'
Convertible threshold trading days	'20 days	'	'
Convertible threshold consecutive trading days	'30 days	'	'
Convertible threshold minimum percentage	130.00%	'	'
Debt instrument, convertible, if-converted value in excess of principal	$1,000	'	'
Convertible, threshold maximum percentage	98.00%	'	'
Purchase price as a percentage on principal amount of the notes upon the occurrence of a fundamental change	100.00%	'	'
Additional effective rate of interest to be used on amortized carrying value	5.12%	'	'
Total estimated fair value of the notes	155,400,000	'	'
Closing price of common stock	$8.76	'	'
1.75% Convertible Senior Notes Due June 1, 2018 [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Debt instrument issued	'	'	150,000,000
Debt instrument interest percentage	'	'	1.75%
Net proceeds from issuance of debt	'	144,500,000	'
Remaining contractual life of senior notes	'5 years	'	'
Debt instrument discount to be amortized	39,000,000	'	'
Debt issuance cost	5,500,000	'	'
Deferred tax liability	$17,000,000	'	'

Convertible_Senior_Notes_Compo

Convertible Senior Notes - Components of Convertible Senior Notes (Details) (USD $)	3 Months Ended
	Mar. 29, 2014	30-May-13	Mar. 29, 2014	Mar. 29, 2014	Mar. 29, 2014
		1.75% Convertible Senior Notes Due June 1, 2018 [Member]	1.75% Convertible Senior Notes Due June 1, 2018 [Member]	1.75% Convertible Senior Notes Due June 1, 2018 [Member]	1.75% Convertible Senior Notes Due June 1, 2018 [Member]
			Additional Paid-in Capital [Member]	Other Noncurrent Assets [Member]	Long-term Debt [Member]
Debt Instrument [Line Items]	'	'	'	'	'
Debt instrument, convertible, if-converted value in excess of principal	$1,000	'	'	'	'
Principal amount	'	150,000,000	'	'	150,000,000
Debt discount	'	'	'	'	-45,000,000
Equity component	'	'	45,000,000	'	'
Initial transaction amounts and debt issuance cost	'	'	'	3,872,000	'
Debt issuance cost	'	'	-1,659,000	'	'
Initial transaction amounts, long-term debt	'	'	'	'	105,000,000
Contractual interest expense	657,000	'	'	'	'
Initial transaction amount and net carrying amount, APIC	'	'	43,341,000	'	'
Amortization of debt issuance cost	'	'	'	-518,000	'
Amortization of debt discount	'	'	'	'	6,024,000
Net carrying amount, other non-current assets	'	'	'	3,354,000	'
Net carrying amount, long-term debt	'	'	'	'	$111,024,000

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. 29, 2014
Debt Disclosure [Abstract]	'
Contractual interest expense	$657
Amortization of debt issuance costs	160
Amortization of debt discount	1,860
Total interest expense recognized related to notes prior to capitalization of interest	$2,677

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

In Millions, except Per Share data, unless otherwise specified

Mar. 29, 2014

Mar. 29, 2014

Mar. 29, 2014

Mar. 29, 2014

Mar. 30, 2013

Dec. 29, 2012

Dec. 28, 2013

Dec. 28, 2013

Mar. 29, 2014

Mar. 30, 2013

Mar. 29, 2014

Mar. 29, 2014

NASDAQ Telecom Composite Index [Member]

IGN Index [Member]

Performance Stock Units Grants [Member]

Performance Stock Units Grants [Member]

Performance Stock Units Grants [Member]

PSUs [Member]

PSUs [Member]

Restricted Stock Units [Member]

Restricted Stock Units [Member]

2007 Equity Incentive Plan [Member]

2007 Equity Incentive Plan [Member]

Minimum [Member]

Maximum [Member]

NASDAQ Telecom Composite Index [Member]

NASDAQ Telecom Composite Index [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Granted options to employees to purchase shares of common stock

19.2

'

'

'

'

'

'

'

'

'

'

'

Closing price of common stock

$8.76

'

'

'

'

'

'

'

'

'

'

'

Number of shares available for grant cost

0.5

'

'

'

'

'

'

'

'

'

'

'

Amortization of stock-based compensation

'

'

'

$0.40

$0.80

'

'

'

$5.10

$6.90

'

'

Ranges of number of shares issued on vesting of PSUs

'

'

'

'

'

'

0

1.5

'

'

0

1.5

Shares of PSUs to executive officers

'

0.6

0.3

'

'

0.5

'

'

'

'

'

'

Amortization of stock based compensation expense offset

'

'

'

'

0.6

'

'

'

'

'

'

'

Decrease in fair value

'

'

'

'

$1.40

'

'

'

'

'

'

'

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Company's Equity Award Activity - Options (Details) (USD $)	3 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Restricted Stock Units [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Amortization of stock-based compensation	$5,100,000	$6,900,000
Stock Options [Member]	'	'
Number of Options	'	'
Number of Options, beginning balance	6,367	'
Number of options, granted	25	'
Number of Options, exercised	-227	'
Number of Options, canceled	-30	'
Number of Options, ending balance	6,135	'
Number of Options, vested and expected to vest	6,130	'
Number of Options, exercisable	5,976	'
Weighted-Average Exercise Price Per Share	'	'
Weighted-Average Exercise Price Per Share, beginning balance	$7.26	'
Weighted-Average Exercise Per Share, Options granted	$9.02	'
Weighted-Average Exercise Price Per Share, Options exercised	$5.85	'
Weighted-Average Exercise Price Per Share, Options canceled	$10.30	'
Weighted-Average Exercise Price Per Share, ending balance	$7.30	'
Average Exercise Price Per Share, Exercisable	$7.29	'
Aggregate Intrinsic Value	'	'
Aggregate Intrinsic Value, beginning balance	17,452,000	'
Aggregate Intrinsic Value, Options exercised	649,000	'
Aggregate Intrinsic Value, ending balance	10,841,000	'
Aggregate Intrinsic Value, Vested and expected to vest	10,835,000	'
Aggregate Intrinsic Value, Exercisable	$10,636,000	'

Stockholders_Equity_Summary_of1

Stockholders' Equity - Summary of Company's Equity Award Activity - RSUs (Details) (Restricted Stock Units [Member], USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014
Restricted Stock Units [Member]	'
Number of Restricted Stock Units	'
Number of Restricted/Performance Stock Units, beginning balance	6,583
Number of Restricted Stock Units, granted	490
Number of Restricted Stock Units, released	-1,541
Number of Restricted Stock Units, canceled	-146
Number of Restricted/Performance Stock Units, ending balance	5,386
Number of Restricted Stock Units, Expected to vest	5,198
Weighted- Average Grant Date Fair Value Per Share	'
Weighted-Average Grant Date Fair Value Per Share, beginning balance	$7.72
Weighted-Average Grant Date Fair Value Per Share, granted	$8.64
Weighted-Average Grant Date Fair Value Per Share, released	$7.91
Weighted-Average Grant Date Fair Value Per Share, canceled	$7.02
Weighted-Average Grant Date Fair Value Per Share, ending balance	$7.77
Aggregate Intrinsic Value	'
Aggregate Intrinsic Value, beginning balance	$64,443
Aggregate Intrinsic Value, RSUs released	12,981
Aggregate Intrinsic Value, ending balance	47,181
Aggregate Intrinsic Value, Expected to vest	$45,539

Stockholders_Equity_Summary_of2

Stockholders' Equity - Summary of Company's Equity Award Activity - PSUs (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
PSUs [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	49.00%	55.00%
Number of Performance Stock Units	'	'
Number of Restricted/Performance Stock Units, beginning balance	721	'
Number of Performance Stock Units, granted	338	'
Number of Performance Stock Units, released	-255	'
Number of Performance Stock Units, canceled	-41	'
Number of Restricted/Performance Stock Units, ending balance	763	721
Number of Restricted Stock Units, Expected to vest	541	'
Weighted- Average Grant Date Fair Value Per Share	'	'
Weighted-Average Grant Date Fair Value Per Share, beginning balance	$7.04	'
Weighted-Average Grant Date Fair Value Per Share, granted	$6.62	'
Weighted-Average Grant Date Fair Value Per Share, released	$6.36	'
Weighted-Average Grant Date Fair Value Per Share, canceled	$7.25	'
Weighted-Average Grant Date Fair Value Per Share, ending balance	$7.04	$7.04
Aggregate Intrinsic Value	'	'
Aggregate Intrinsic Value, beginning balance	$7,054	'
Aggregate Intrinsic Value, PSUs released	2,097	'
Aggregate Intrinsic Value, ending balance	6,684	7,054
Aggregate Intrinsic Value, Expected to vest	$4,738	'
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, NASDAQ Telecom Composite Index, Expected Volatility Rate	'	23.00%
Risk-free interest rate	0.66%	0.42%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Correction with NASDAQ Telecom Composite Index	'	56.00%
Minimum [Member] | PSUs [Member]	'	'
Weighted- Average Grant Date Fair Value Per Share	'	'
Weighted-Average Grant Date Fair Value Per Share, granted	$6.61	$6.27
Maximum [Member] | PSUs [Member]	'	'
Weighted- Average Grant Date Fair Value Per Share	'	'
Weighted-Average Grant Date Fair Value Per Share, granted	$7.60	$7.06
Fiscal Year 2013 Grant [Member]	'	'
Number of Performance Stock Units	'	'
Number of Performance Stock Units, released	-300	'

Stockholders_Equity_Total_Stoc

Stockholders' Equity - Total Stock Based Compensation Cost for Instruments Granted but Not Yet Amortized (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Stock options, Unrecognized Compensation Expense, Net	$543
Stock options, Weighted-Average Period (in years)	'1 year 7 months 28 days
Restricted Stock Units [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Unrecognized Compensation Expense, Net	28,289
Weighted-Average Period (in years)	'2 years 3 months 15 days
PSUs [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Unrecognized Compensation Expense, Net	$2,759
Weighted-Average Period (in years)	'1 year 9 months 18 days

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	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014
			PSUs [Member]	PSUs [Member]	PSUs [Member]	PSUs [Member]	PSUs [Member]	PSUs [Member]	Stock Compensation Plan [Member]	Stock Compensation Plan [Member]	Stock Compensation Plan [Member]
					Minimum [Member]	Minimum [Member]	Maximum [Member]	Maximum [Member]			Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Weighted-Average Grant Date Fair Value Per Share, granted	'	'	$6.62	'	$6.61	$6.27	$7.60	$7.06	'	'	'
Volatility	'	'	49.00%	55.00%	'	'	'	'	'	'	52.00%
Risk-free interest rate	'	'	0.66%	0.42%	'	'	'	'	'	'	1.30%
Expected life	'	'	'	'	'	'	'	'	'	'	'4 years 3 months 18 days
Estimated fair value	'	'	'	'	'	'	'	'	'	'	$3.85
Stock-based compensation expense	$6,672	$7,975	'	'	'	'	'	'	$388	$803	'
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	'	'	60.00%	'	'	'	'	'	'	'	'

Stockholders_Equity_Estimated_

Stockholders' Equity - Estimated Fair Value of ESPP Shares (Details) (USD $)	3 Months Ended			12 Months Ended	3 Months Ended			12 Months Ended	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014	Dec. 28, 2013
			PSUs [Member]	PSUs [Member]	Employee Stock Purchase Plans [Member]	Employee Stock Purchase Plans [Member]	Minimum [Member]	Minimum [Member]	Maximum [Member]	Maximum [Member]
							PSUs [Member]	PSUs [Member]	PSUs [Member]	PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'
Weighted-Average Grant Date Fair Value Per Share, granted	'	'	$6.62	'	'	'	$6.61	$6.27	$7.60	$7.06
Volatility	'	'	49.00%	55.00%	51.00%	46.00%	'	'	'	'
Risk-free interest rate	'	'	0.66%	0.42%	0.11%	0.14%	'	'	'	'
Expected life	'	'	'	'	'6 months	'6 months	'	'	'	'
Estimated fair value	'	'	'	'	$2.57	$1.87	'	'	'	'
Stock-based compensation expense	$6,672	$7,975	'	'	$791	$708	'	'	'	'

Stockholders_Equity_Summary_of3

Stockholders' Equity - Summary of Effects of Stock-Based Compensation on Company's Balance Sheets (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Stock-Based Compensation Effects in Inventory [Member]	'	'
Effects Of Stock Based Compensation [Line Items]	'	'
Effects Of Stock Based Compensation	$3,219	$3,189
Stock-Based Compensation Effects in Deferred Inventory Cost [Member]	'	'
Effects Of Stock Based Compensation [Line Items]	'	'
Effects Of Stock Based Compensation	14	15
Stock-Based Compensation Effects in Fixed Assets [Member]	'	'
Effects Of Stock Based Compensation [Line Items]	'	'
Effects Of Stock Based Compensation	$139	$145

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. 29, 2014		Mar. 30, 2013
Effects Of Stock Based Compensation [Line Items]	'		'
Stock-based compensation effects included in net loss before income taxes	$5,840		$6,373
Cost of revenue - amortization from balance sheet	832	[1]	1,602	[1]
Allocated Share-based Compensation Expense	6,672		7,975
Cost of Sales [Member]	'		'
Effects Of Stock Based Compensation [Line Items]	'		'
Stock-based compensation effects included in net loss before income taxes	452		486
Research and Development Expense [Member]	'		'
Effects Of Stock Based Compensation [Line Items]	'		'
Stock-based compensation effects included in net loss before income taxes	2,138		3,119
Selling and Marketing Expense [Member]	'		'
Effects Of Stock Based Compensation [Line Items]	'		'
Stock-based compensation effects included in net loss before income taxes	1,720		1,999
General and Administrative Expense [Member]	'		'
Effects Of Stock Based Compensation [Line Items]	'		'
Stock-based compensation effects included in net loss before income taxes	$1,530		$769
[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. 29, 2014	Mar. 30, 2013
Income Tax Disclosure [Abstract]	'	'
Provision for income taxes	$248	$331
Provision for income tax percentage	-6.00%	-2.20%
Pre-tax income (loss)	$4,126	$14,948
Federal statutory rate	35.00%	'

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. 29, 2014	Mar. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	$142,815	$124,625
Operating Segments [Member] | United States [Member]	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	110,691	79,073
Operating Segments [Member] | Other Americas [Member]	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	3,536	718
Operating Segments [Member] | Americas [Member]	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	114,227	79,791
Operating Segments [Member] | Europe, Middle East and Africa [Member]	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	25,613	38,806
Operating Segments [Member] | Asia Pacific [Member]	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	$2,975	$6,028

Segment_Information_Property_P

Segment Information - Property, Plant and Equipment, Net (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Geographic Information For Property Plant And Equipment [Line Items]	'	'
Total property, plant and equipment, net	$78,801	$79,668
Operating Segments [Member] | United States [Member]	'	'
Geographic Information For Property Plant And Equipment [Line Items]	'	'
Total property, plant and equipment, net	76,029	76,850
Operating Segments [Member] | Other Americas [Member]	'	'
Geographic Information For Property Plant And Equipment [Line Items]	'	'
Total property, plant and equipment, net	275	319
Operating Segments [Member] | Europe, Middle East and Africa [Member]	'	'
Geographic Information For Property Plant And Equipment [Line Items]	'	'
Total property, plant and equipment, net	1,027	1,451
Operating Segments [Member] | Asia Pacific [Member]	'	'
Geographic Information For Property Plant And Equipment [Line Items]	'	'
Total property, plant and equipment, net	$1,470	$1,048

Guarantees_Additional_Informat

Guarantees - Additional Information (Details)	3 Months Ended
	Mar. 29, 2014
Minimum [Member]	'
Guarantor Obligations [Line Items]	'
Product warranty period	'1 year
Maximum [Member]	'
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. 29, 2014		Mar. 30, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]	'		'
Beginning balance	$22,908		$16,482
Charges to operations	5,561		4,168
Utilization	-3,242		-2,083
Change in estimate	1,158	[1]	-1,895	[1]
Balance at the end of the period	$26,385		$16,672
[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 and the resulting impact of these changes on the Company’s estimate of expected future returns, as well as changes in the estimated cost of replacing failed units with either repaired or new units.