iRobot (IRBT) 10-Q 1 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended	9 Months Ended
	Sep. 28, 2013	Sep. 28, 2013	Oct. 29, 2013
Entity Information [Line Items]	'	'	'
Document Type	'	'10-Q	'
Amendment Flag	'	'false	'
Document Period End Date	28-Sep-13	'	'
Document Fiscal Year Focus	'	'2013	'
Document Fiscal Period Focus	'	'Q3	'
Trading Symbol	'	'IRBT	'
Entity Registrant Name	'	'IROBOT CORP	'
Entity Central Index Key	'	'0001159167	'
Current Fiscal Year End Date	'	'--12-28	'
Entity Filer Category	'	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	'	28,865,070

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$139,731	$126,770
Short term investments	16,948	12,430
Accounts receivable, net of allowance of $81 and $111 at September 28, 2013 and December 29, 2012, respectively	54,027	29,413
Unbilled revenue	1,556	1,196
Inventory	48,853	36,965
Deferred tax assets	19,517	19,266
Other current assets	6,131	8,853
Total current assets	286,763	234,893
Property and equipment, net	24,039	24,953
Deferred tax assets	10,464	8,792
Goodwill	48,751	48,951
Finite-Lived Intangible Assets, Net	23,587	28,224
Other assets	10,501	8,500
Total assets	404,105	354,313
Current liabilities:	'	'
Accounts payable	46,644	42,515
Accrued expenses	13,409	13,642
Accrued compensation	14,868	11,864
Deferred Revenue, Current	2,026	6,257
Total current liabilities	76,947	74,278
Long term liabilities	4,556	4,218
Commitments and contingencies (Note 6)	'	'
Redeemable convertible preferred stock, 5,000,000 shares authorized and none outstanding	0	0
Common stock, $0.01 par value, 100,000,000 shares authorized; 28,807,393 and 27,781,659 shares issued and outstanding at September 28, 2013 and December 29, 2012, respectively	288	278
Additional paid-in capital	222,311	199,903
Retained earnings	99,890	75,437
Accumulated other comprehensive income	113	199
Total stockholders' equity	322,602	275,817
Total liabilities, redeemable convertible preferred stock and stockholders' equity	$404,105	$354,313

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, except Share data, unless otherwise specified
Net allowances on Accounts receivables	$81	$111
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	28,807,393	27,781,659
Common stock, shares outstanding	28,807,393	27,781,659

Consolidated_Statements_of_Inc

Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013		Sep. 29, 2012
Revenue:	'	'	'		'
Product revenue	$122,647	$121,174	$352,018		$320,676
Contract revenue	1,854	5,124	9,040		14,874
Total revenue	124,501	126,298	361,058		335,550
Cost of revenue:	'	'	'		'
Cost of product revenue	69,628	65,852	195,316	[1]	179,174	[1]
Cost of contract revenue	812	1,970	3,549		6,532
Total cost of revenue	70,440	67,822	198,865		185,706
Gross margin	54,061	58,476	162,193		149,844
Operating expenses:	'	'	'		'
Research and development	15,212	13,040	45,617	[1]	41,722	[1]
Selling and marketing	16,317	11,376	49,323	[1]	41,685	[1]
General and administrative	11,495	11,326	39,348	[1]	32,390	[1]
Total operating expenses	43,024	35,742	134,288		115,797
Operating income	11,037	22,734	27,905		34,047
Other income (expense), net	152	197	-49		477
Income before income taxes	11,189	22,931	27,856		34,524
Income tax expense	3,385	7,724	3,403		11,289
Net income	7,804	15,207	24,453		23,235
Net income per share	'	'	'		'
Basic, in dollars per share	$0.27	$0.55	$0.86		$0.84
Diluted, in dollars per share	$0.26	$0.54	$0.84		$0.82
Number of shares used in calculations per share	'	'	'		'
Basic, in shares	28,733	27,650	28,359		27,520
Diluted, in shares	29,582	28,321	29,207		28,323
Total stock-based compensation recorded in the three months ended March 30, 2013 and March 31, 2012 included in the above figures breaks down by expense classification as follows:	'	'	'		'
Stock based compensation	'	'	9,669		8,023
Cost of product revenue	'	'	'		'
Total stock-based compensation recorded in the three months ended March 30, 2013 and March 31, 2012 included in the above figures breaks down by expense classification as follows:	'	'	'		'
Stock based compensation	250	289	496		715
Research and development	'	'	'		'
Total stock-based compensation recorded in the three months ended March 30, 2013 and March 31, 2012 included in the above figures breaks down by expense classification as follows:	'	'	'		'
Stock based compensation	669	365	1,963		1,271
Selling and marketing	'	'	'		'
Total stock-based compensation recorded in the three months ended March 30, 2013 and March 31, 2012 included in the above figures breaks down by expense classification as follows:	'	'	'		'
Stock based compensation	348	158	832		574
General and administrative	'	'	'		'
Total stock-based compensation recorded in the three months ended March 30, 2013 and March 31, 2012 included in the above figures breaks down by expense classification as follows:	'	'	'		'
Stock based compensation	$2,210	$1,796	$6,378		$5,463
[1]	Total stock-based compensation recorded in the three and nine months ended SeptemberB 28, 2013 and SeptemberB 29, 2012 included in the above figures breaks down by expense classification as follows:B Three Months EndedB Nine Months EndedB SeptemberB 28, 2013B SeptemberB 29, 2012B SeptemberB 28, 2013B SeptemberB 29, 2012Cost of product revenue$250B $289B $496B $715Research and development669B 365B 1,963B 1,271Selling and marketing348B 158B 832B 574General and administrative2,210B 1,796B 6,378B 5,463

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Statement of Partners' Capital [Abstract]	'	'	'	'
Net income, as reported	$7,804	$15,207	$24,453	$23,235
Other comprehensive income (loss), net of tax:	'	'	'	'
Unrealized gains/(losses) on investments, net of tax	75	50	-86	104
Total comprehensive income	$7,879	$15,257	$24,367	$23,339

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012
Cash flows from operating activities:	'	'
Net income	$24,453	$23,235
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	9,029	8,181
Loss on disposal of property and equipment	-351	778
Goodwill and Intangible Asset Impairment	1,988	0
Stock-based compensation	9,669	8,023
Deferred income taxes, net	-662	-2,855
Tax benefit of excess stock based compensation deductions	-2,238	-1,461
Non-cash director deferred compensation	33	64
Changes in operating assets and liabilities - (use) source	'	'
Accounts receivable	-24,614	-10,041
Unbilled revenue	-360	669
Inventory	-11,888	-1,503
Other assets	2,697	3,266
Accounts payable	4,129	-10,089
Accrued expenses	-216	1,596
Accrued compensation	3,004	-8,842
Deferred revenue and customer advances	-4,231	591
Long term liabilities	338	-315
Net cash provided by operating activities	10,780	11,297
Cash flows from investing activities:	'	'
Additions of property and equipment	-5,309	-4,067
Payments for (Proceeds from) Other Investing Activities	2,000	6,000
Purchases of investments	-12,897	-5,086
Sales of investments	8,044	2,500
Proceeds from Sales of Assets, Investing Activities	650	0
Net cash used in investing activities	-11,512	-12,653
Cash flows from financing activities:	'	'
Proceeds from stock option exercises	12,364	4,022
Income tax withholding payment associated with restricted stock vesting	-909	-777
Tax benefit of excess stock-based compensation deductions	2,238	1,461
Net cash provided by financing activities	13,693	4,706
Net increase in cash and cash equivalents	12,961	3,350
Cash and cash equivalents, at beginning of period	126,770	166,308
Cash and cash equivalents, at end of period	139,731	169,658
Supplemental disclosure of cash flow information:	'	'
Cash paid for income taxes	$7,062	$7,166

Description_of_Business

Description of Business	9 Months Ended
	Sep. 28, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Description of Business	'
	1. Description of Business
	iRobot Corporation (“iRobot” or the “Company”) develops robotics and artificial intelligence technologies and applies these technologies in producing and marketing robots. The majority of the Company’s revenue is generated from product sales and, to a lesser extent, government and commercial research and development contracts.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 28, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying consolidated financial statements include those of iRobot and its subsidiaries, after elimination of all intercompany accounts and transactions. iRobot has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America.
	The accompanying unaudited financial data as of September 28, 2013 and for the three and nine months ended September 28, 2013 and September 29, 2012 has been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. The year-end balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in its Annual Report on Form 10-K for the fiscal year ended December 29, 2012, filed with the SEC on February 15, 2013.
	In the opinion of management, all adjustments necessary to state fairly its statement of financial position as of September 28, 2013 and results of operations and cash flows for the periods ended September 28, 2013 and September 29, 2012 have been made. The results of operations and cash flows for any interim period are not necessarily indicative of the operating results and cash flows for the full fiscal year or any future periods.
	Reorganization
	In fiscal year 2012, the Company initiated a reorganization that resulted in, among other things, the centralization of all of the Company's engineering and operations activities. This reorganization was completed at the beginning of fiscal year 2013. In conjunction with this reorganization, the Company reviewed the financial statement classification of its costs and expenses. As a result of this review, the Company decided to classify certain expenses differently than had been classified and presented in prior periods to provide a more clear understanding of the Company's financial performance. As part of this review, the Company also evaluated the impact of the reorganization on its segment reporting and determined that certain modifications were necessary to present the segment information as now viewed by the Company's chief operating decision maker. Although the classification of certain expenses on the income statement has changed in fiscal year 2013 as compared to prior periods, the Company recast the financial results of prior periods in a manner consistent with the fiscal year 2013 presentation for comparability purposes. The reclassified amounts reflected in the consolidated statements of income for the three and nine months ended September 29, 2012 included herein conform to the fiscal year 2013 presentation. This reclassification of costs and expenses did not impact previously reported net income or earnings per share as the changes only impacted the categorization of costs within the consolidated statements of income for the periods in question. Consequently, the classification changes did not impact previously presented consolidated balance sheets, statements of cash flow or statements of stockholders' equity.
	Revision of Consolidated Balance Sheet as of December 29, 2012
	During the three month period ended March 30, 2013, the Company identified a classification error related to its reserves for uncertain tax positions on its December 29, 2012 consolidated balance sheet. The Company had recorded a gross income tax receivable in current assets and a gross uncertain tax positions liability against that receivable in current liabilities as of December 29, 2012. In addition, the Company misclassified certain liabilities for uncertain tax positions in current and long-term liabilities. The impact of the errors on the December 29, 2012 consolidated balance sheet was a decrease in Other Current Assets of $2.7 million, an increase in Other Assets of $0.2 million, a decrease in Accrued Expenses of $2.9 million, and an increase in Long-term Liabilities of $0.4 million. These adjustments were not considered to be material, individually or in the aggregate, to previously issued financial statements. The Company has revised its December 29, 2012 consolidated balance sheet to correct these errors as reflected herein. This revision had no impact on the consolidated statement of income, the consolidated statement of comprehensive income, or total cash flows from operating activities, investing activities, or financing activities.
	Out of Period Adjustment
	During the third quarter of 2013, the Company identified an immaterial error to previously reported depreciation expense due to the use of an incorrect useful life on a leasehold improvement asset. The recorded out of period adjustment to cost of revenue and operating expenses resulted in a $0.6 million increase in third quarter 2013 net income. The adjustment did not have a material impact on the reported financial position or results of operations for the quarter ended September 28, 2013. Additionally, had this adjustment been recorded in the prior periods to which it relates (fiscal 2011, 2012 and the six month period ended June 29, 2013), the impact would not have been material to the reported financial position or results of operations for those periods.
	Use of Estimates
	The preparation of these financial statements in conformity with accounting principles generally accepted in the United States requires the Company to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and disclosure of contingent assets and liabilities. On an ongoing basis, management evaluates these estimates and judgments, including those related to revenue recognition, sales returns, bad debts, warranty claims, inventory reserves, valuation of investments, assumptions used in valuing stock-based compensation instruments and income taxes. The Company bases these estimates on historical and anticipated results and trends and on various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. By their nature, estimates are subject to an inherent degree of uncertainty. Actual results may differ from the Company’s estimates.
	Fiscal Year-End
	The Company operates and reports using a 52-53 week fiscal year ending on the Saturday closest to December 31. Accordingly, the Company’s fiscal quarters end on the Saturday that falls closest to the last day of the third month of each quarter.
	Revenue Recognition
	The Company derives its revenue from product sales and, to a lesser extent, government research and development contracts, and commercial research and development contracts. The Company sells products directly to customers and indirectly through resellers and distributors. The Company recognizes revenue from sales of robots under the terms of the customer agreement upon transfer of title and risk of loss to the customer, net of estimated returns, provided that collection is determined to be reasonably assured and no significant obligations remain. Sales to domestic resellers of home robots are typically subject to agreements allowing for limited rights of return, rebates and price protection. Accordingly, the Company reduces revenue for its estimates of liabilities for these rights of return at the time the related sale is recorded. The Company makes an estimate of sales returns for products sold by domestic resellers directly based on historical returns experience and other relevant data. The Company’s international distributor agreements do not currently allow for product returns and, as a result, no reserve for returns is established for this group of customers. The Company has aggregated and analyzed historical returns from domestic resellers and end users which form the basis of its estimate of future sales returns by resellers or end users. When a right of return exists, the provision for these estimated returns is recorded as a reduction of revenue at the time that the related revenue is recorded. If actual returns differ significantly from its estimates, such differences could have a material impact on the Company’s results of operations for the period in which the returns become known. The estimates for returns are adjusted periodically based upon historical rates of returns. The estimates and reserve for rebates and price protection are based on specific programs, expected usage and historical experience. Actual results could differ from these estimates.
	Under cost-plus-fixed-fee (“CPFF”) type contracts, the Company recognizes revenue based on costs incurred plus a pro rata portion of the total fixed fee. Costs incurred include labor and material that are directly associated with individual CPFF contracts plus indirect overhead and general and administrative type costs based upon billing rates submitted by the Company to the Defense Contract Management Agency (“DCMA”). Annually, the Company submits final indirect billing rates to DCMA based upon actual costs incurred throughout the year. In the situation where the Company’s final actual billing rates are greater than the estimated rates currently in effect, the Company records a cumulative revenue adjustment in the period in which the rate differential is collected from the customer. These final billing rates are subject to audit by the Defense Contract Audit Agency (“DCAA”), which can occur several years after the final billing rates are submitted and may result in material adjustments to revenue recognized based on estimated final billing rates. As of September 28, 2013, fiscal year 2007 is under audit by DCAA, and fiscal years 2008 through 2012 are open for audit by DCAA. In the situation where the Company’s anticipated actual billing rates will be lower than the provisional rates currently in effect, the Company records a cumulative revenue adjustment in the period in which the rate differential is identified. Revenue on firm fixed price (“FFP”) contracts is recognized using the percentage-of-completion method. For government product FFP contracts, revenue is recognized as the product is shipped or in accordance with the contract terms. Costs and estimated gross margins on contracts are recorded as revenue as work is performed based on the percentage that incurred costs compare to estimated total costs utilizing the most recent estimates of costs and funding. Changes in job performance, job conditions, and estimated profitability, including those arising from final contract settlements and government audits, may result in revisions to costs and income and are recognized in the period in which the revisions are determined. Since many contracts extend over a long period of time, revisions in cost and funding estimates during the progress of work have the effect of adjusting earnings applicable to past performance in the current period. When the current contract estimate indicates a loss, a provision is made for the total anticipated loss in the current period. Revenue earned in excess of billings, if any, is recorded as unbilled revenue. Billings in excess of revenue earned, if any, are recorded as deferred revenue.
	Accounting for Share-Based Payments
	The Company accounts for share-based payments to employees, including grants of employee stock options and awards in the form of restricted shares and restricted stock units by establishing the fair value of each option grant using the Black-Scholes option pricing model and the fair value of awards based on stock price at the time of grant. The fair value of share-based payments is recorded by the Company as a charge against earnings. The Company recognizes share-based payment expense over the requisite service period of the underlying grants and awards. The Company’s share-based payment awards are accounted for as equity instruments.
	Net Income Per Share
	The following table presents the calculation of both basic and diluted net income per share:
		Three Months Ended				Nine Months Ended
		(In thousands, except per share amounts)
		28-Sep-13		29-Sep-12		28-Sep-13		29-Sep-12
	Net income	$	7,804	$	15,207	$	24,453	$	23,235
	Weighted-average shares outstanding	28,733		27,650		28,359		27,520
	Dilutive effect of employee stock options and restricted shares	849		671		848		803
	Diluted weighted-average shares outstanding	29,582		28,321		29,207		28,323
	Basic income per share	$	0.27	$	0.55	$	0.86	$	0.84
	Diluted income per share	$	0.26	$	0.54	$	0.84	$	0.82
	Restricted stock units and stock options representing approximately 0.1 million and 0.9 million shares of common stock for the three month periods ended September 28, 2013 and September 29, 2012, respectively, and approximately 0.7 million and 0.7 million shares of common stock for the nine month periods ended September 28, 2013 and September 29, 2012, respectively, were excluded from the computation of diluted earnings per share for these periods because their effect would have been antidilutive.
	Income Taxes
	The Company is subject to taxation in the United States and various states and foreign jurisdictions. The statute of limitations for examination by the Internal Revenue Service ("IRS") is closed for fiscal years prior to 2010. During the nine month period ended September 28, 2013, the IRS completed its examination of the Company's tax returns for the years 2008, 2009 and 2010. The statute of limitations for examination by state tax authorities is closed for fiscal years prior to 2009. Federal carryforward attributes that were generated prior to fiscal year 2010, and state carryforward attributes that were generated prior to fiscal year 2009 may still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in a period for which the statute of limitations is still open.
	Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.
	The Company monitors the realization of its deferred tax assets based on changes in facts and circumstances, for example recurring periods of income for tax purposes following historical periods of cumulative losses or changes in tax laws or regulations. The Company's income tax provisions and its assessment of the ability to realize its deferred tax assets involve significant judgments and estimates.
	The Company recorded a tax provision of $3.4 million and $7.7 million for the three month periods ended September 28, 2013 and September 29, 2012, respectively. The $3.4 million provision for the three month period ended September 28, 2013 resulted in an effective income tax rate of 30.3%. The $7.7 million provision for the three month period ended September 29, 2012 resulted in an effective income tax rate of 33.7%. The decrease in the effective income tax rate from 33.7% for the three month period ended September 29, 2012 to 30.3% for the three month period ended September 28, 2013 was primarily due to the inclusion of the federal research and development tax credit in the 2013 income tax provision, which was not enacted into law for inclusion in the 2012 income tax provision.
	The Company recorded a tax provision of $3.4 million and $11.3 million for the nine month periods ended September 28, 2013 and September 29, 2012, respectively. The $3.4 million provision for the nine month period ended September 28, 2013 resulted in an effective tax rate of 12.2%. The $11.3 million provision for the nine month period ended September 29, 2012 resulted in an effective tax rate of 32.7%. The decrease in the effective income tax rate from 32.7% for the nine month period ended September 29, 2012 to 12.2% for the nine month period ended September 28, 2013 was primarily due to the release of $2.7 million of certain income tax reserves due to favorable conclusions of the IRS examination of the Company's income tax returns for the years 2008, 2009 and 2010, the inclusion of the federal research and development tax credit in the 2013 income tax provision, which was not enacted into law for inclusion in the 2012 income tax provision, and the retroactive reinstatement of federal research and development tax credits in 2013. In January 2013, legislation was enacted that included the extension of the federal research and development tax credits. The legislation retroactively reinstated research and development tax credits for 2012 and extended them through December 31, 2013. As a result, the Company recorded a discrete benefit of $1.7 million related to 2012 during the nine month period ended September 28, 2013.
	The Company anticipates the settlement of state tax audits may be finalized within the next twelve months and could result in a decrease in its unrecognized gross tax benefits of up to $0.7 million.
	In September 2013, the U.S. Department of the Treasury and the IRS issued final regulations addressing the acquisition, production and improvement of tangible property, and also proposed regulations addressing the disposition of property.  These regulations replace previously issued temporary regulations and are effective for tax years beginning January 1, 2014, with optional adoption permitted in 2013.  The Company is in the process of analyzing the impact of these new regulations but does not believe they will have a material impact on the Company's consolidated financial statements.
	Fair Value Measurements
	The authoritative guidance for fair value establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
	Financial Assets
	The Company’s financial assets measured at fair value on a recurring basis at September 28, 2013, were as follows:
		Fair Value Measurements as of
		28-Sep-13
		Level 1		Level 2		Level 3
		(In thousands)
	Description
	Assets:
	Money market funds	$	83,822	$	—	$	—
	Corporate and government bonds	—		16,948		—
	Total assets measured at fair value	$	83,822	$	16,948	$	—
	The Company’s financial assets measured at fair value on a recurring basis at December 29, 2012, were as follows:
		Fair Value Measurements as of
		29-Dec-12
		Level 1		Level 2		Level 3
		(In thousands)
	Description
	Assets:
	Money market funds	$	88,144	$	—	$	—
	Corporate bonds	—		12,430		—
	Total assets measured at fair value	$	88,144	$	12,430	$	—
In each table above, the bond investments are valued based on observable market values as of the Company’s reporting date and are included in Level 2. The bond investments are recorded at fair value and marked-to-market at the end of each reporting period. The realized and unrealized gains and losses are included in comprehensive income for that period. The fair value of the Company’s bond investment is included in short term investments in its consolidated balance sheet.
Goodwill
Goodwill is recorded as the difference, if any, between the aggregate consideration paid for an acquisition and the fair value of the net tangible and intangible assets acquired. The Company evaluates goodwill for impairment at the reporting unit level (operating segment or one level below an operating segment) annually or more frequently if the Company believes indicators of impairment exist. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then a two-step goodwill impairment test is performed. The first step of the impairment test involves comparing the fair values of the applicable reporting units with their aggregate carrying values, including goodwill. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, the Company performs the second step of the goodwill impairment test to determine the amount of impairment loss. The second step of the goodwill impairment test involves comparing the implied fair value of the affected reporting unit’s goodwill with the carrying value of that goodwill.
Recent Accounting Pronouncements
In July 2013, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update related to the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  This new guidance clarifies guidance and eliminates diversity in practice on the presentation of unrecognized tax benefits when certain situations exist at the reporting date.  This new guidance is effective for annual reporting periods beginning on or after December 15, 2013 and subsequent interim periods.  We are currently assessing the impact, if any, on our consolidated financial statements.
In February 2013, the FASB issued guidance requiring disclosure of amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present either on the face of the statement of operations or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For amounts not reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. This guidance was effective prospectively for the Company for annual and interim periods beginning January 1, 2013. The impact of these amendments on the Company’s consolidated financial statements was not material.
From time to time, new accounting pronouncements are issued by FASB that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that recently issued standards, which are not yet effective, will not have a material impact on the Company’s consolidated financial statements upon adoption.

Inventory

Inventory	9 Months Ended
	Sep. 28, 2013
Inventory Disclosure [Abstract]	'
Inventory	'
	3. Inventory
	Inventory consists of the following:
		28-Sep-13		29-Dec-12
		(In thousands)
	Raw materials	$	5,754	$	8,849
	Work in process	—		60
	Finished goods	43,099		28,056
		$	48,853	$	36,965

Stock_Option_Plans

Stock Option Plans	9 Months Ended
	Sep. 28, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock Option Plans	'
	4. Stock Option Plans
	The Company has options outstanding under four stock incentive plans: the 1994 Stock Option Plan (the “1994 Plan”), the 2004 Stock Option and Incentive Plan (the “2004 Plan”), the 2005 Stock Option and Incentive Plan (the "2005 Plan") and the Evolution Robotics, Inc. 2007 Stock Plan (the "2007 Plan" and together with the 1994 Plan, the 2004 Plan and the 2005 Plan, the “Plans”). The 2005 Plan is the only one of the four plans under which new awards may currently be granted. Under the 2005 Plan, which became effective October 10, 2005, 1,583,682 shares were initially reserved for issuance in the form of incentive stock options, non-qualified stock options, stock appreciation rights, deferred stock awards and restricted stock awards. Additionally, the 2005 Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning in 2007, by 4.5% of the outstanding number of shares of common stock on the immediately preceding December 31. Stock options returned to the Plans, with the exception of those issued under the 2007 Plan, as a result of their expiration, cancellation or termination are automatically made available for issuance under the 2005 Plan. Eligibility for incentive stock options is limited to those individuals whose employment status would qualify them for the tax treatment associated with incentive stock options in accordance with the Internal Revenue Code of 1986, as amended. As of September 28, 2013, there were 3,872,511 shares available for future grant under the 2005 Plan.
	Options granted under the Plans are subject to terms and conditions as determined by the compensation committee of the board of directors, including vesting periods. Options granted under the Plans are exercisable in full at any time subsequent to vesting, generally vest over periods from zero to five years, and expire seven or ten years from the date of grant or, if earlier, 60 or 90 days from employee termination. The exercise price of incentive stock options is equal to the closing price on the NASDAQ Global Market on the date of grant. The exercise price of nonstatutory options may be set at a price other than the fair market value of the common stock.
	On September 6, 2013, the Company granted to certain employees stock options totaling 31,600 shares of the Company's common stock and 74,490 restricted stock units. Each of the above stock options have a per share exercise price of $33.72, the closing price of the Company's common stock on NASDAQ on September 6, 2013. The stock options and restricted stock units generally vest over a four year period.

Accrued_Expenses

Accrued Expenses	9 Months Ended
	Sep. 28, 2013
Accrued Liabilities, Current [Abstract]	'
Accrued Expenses	'
	5. Accrued Expenses
	Accrued expenses consist of the following:
		28-Sep-13		29-Dec-12
		(In thousands)
	Accrued warranty	$	6,688	$	6,057
	Accrued rent	731		696
	Accrued sales tax	676		719
	Accrued direct fulfillment costs	396		999
	Accrued sales commissions	261		475
	Accrued accounting fees	170		155
	Accrued other	4,487		4,541
		$	13,409	$	13,642

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 28, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	6. Commitments and Contingencies
	Lease Obligations
	Rental expense under operating leases for the three months ended September 28, 2013 and September 29, 2012 were $1.1 million and $1.0 million, respectively, and for the nine months ended September 28, 2013 and September 29, 2012 were $3.5 million and $3.2 million, respectively. Future minimum rental payments under operating leases were as follows as of September 28, 2013:
		Operating
		Leases
		(In thousands)
	Remainder of 2013	$	842
	2014	3,109
	2015	3,040
	2016	2,747
	2017	2,505
	Thereafter	5,682
	Total minimum lease payments	$	17,925
	Sales Taxes
	The Company collects and remits sales tax in jurisdictions in which it has a physical presence or it believes nexus exists, which therefore obligates the Company to collect and remit sales tax. The Company continually evaluates whether it has established nexus in new jurisdictions with respect to sales tax. The Company has recorded a liability for potential exposure in several states where there is uncertainty about the point in time at which the Company established a sufficient business connection to create nexus. The Company continues to analyze possible sales tax exposure, but does not currently believe that any individual claim or aggregate claims that might arise will ultimately have a material effect on its consolidated results of operations, financial position or cash flows.
	Guarantees and Indemnification Obligations
	The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these agreements, the Company indemnifies and agrees to reimburse the indemnified party for losses incurred by the indemnified party, generally the Company’s customers, in connection with any patent, copyright, trade secret or other proprietary right infringement claim by any third party with respect to the Company’s products. The term of these indemnification agreements is generally perpetual after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, the Company believes the estimated fair value of these agreements is minimal. Accordingly, the Company has no liabilities recorded for these agreements as of September 28, 2013 and December 29, 2012, respectively.
	Warranty
	The Company provides warranties on most products and has established a reserve for warranty based on identified or estimated warranty costs. The reserve is included as part of accrued expenses (Note 5) in the accompanying balance sheets.
	Activity related to the warranty accrual was as follows:
		Three Months Ended						Nine Months Ended
		September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
		(In thousands)						(In thousands)
	Balance at beginning of period	$	6,322		$	8,990		$	6,057		$	10,306
	Provision	773			1,080			1,832			1,318
	Warranty usage(1)	(407		)	(524		)	(1,201		)	(2,078		)
	Balance at end of period	$	6,688		$	9,546		$	6,688		$	9,546
	-1	Warranty usage includes the expiration of product warranties unutilized.
	Inventory
	Based upon its business outlook, the Company provides purchase orders and material authorizations to its contract manufacturers for future delivery of finished goods. On the basis of these purchase orders and material authorizations, the Company’s contract manufacturers order components from their respective suppliers. Should the Company’s business outlook not materialize as expected, it may be contractually obligated to purchase from the contract manufacturers inventory they have secured on behalf of the Company, which may be in excess of customer demand. The Company continually evaluates whether any such obligation or exposure exists and records a liability in the period in which such obligations or exposure are identified.

Acquisition_of_Evolution_Robot

Acquisition of Evolution Robotics, Inc.	9 Months Ended
	Sep. 28, 2013
Business Combinations [Abstract]	'
Acquisition of Evolution Robotics, Inc.	'
	7. Acquisition of Evolution Robotics, Inc.
	On October 1, 2012, the Company acquired 100% of the equity of Evolution Robotics, Inc. ("Evolution") for $74.8 million in cash, including the effect of working capital adjustments and cash received, with $8.88 million of the purchase price placed into an escrow account to settle certain claims for indemnification for breaches or inaccuracies in Evolution’s representations and warranties, covenants and agreements. Evolution was the developer of Mint and Mint Plus automatic floor cleaning robots, based in Pasadena, California, and is included in the Company's home robots business unit.
	Pro Forma Disclosures (Unaudited)
	The following unaudited pro forma consolidated results of operations for the three and nine month periods ended September 28, 2013 and September 29, 2012 assume that the acquisition of Evolution occurred as of January 1, 2012.
		Three Months Ended				Nine Months Ended
		September 28, 2013		September 29, 2012		September 28, 2013		September 29, 2012
		(In thousands)				(In thousands)
	Revenue	$	124,501	$	131,164	$	361,058	$	344,775
	Net Income	7,804		13,496		24,453		15,703
	These pro forma amounts do not purport to be indicative of the results that would have actually been obtained if the acquisitions had occurred at the beginning of the periods presented or that may be obtained in the future.

Industry_Segment_Geographic_In

Industry Segment, Geographic Information and Significant Customers	9 Months Ended
	Sep. 28, 2013
Segment Reporting [Abstract]	'
Industry Segment, Geographic Information and Significant Customers	'
	8. Industry Segment, Geographic Information and Significant Customers
	The Company operates in two reportable segments, the home robots business unit and the defense and security robots business unit. The nature of products and types of customers for the two segments vary significantly. As such, the segments are managed separately. As a result of the reorganization completed at the beginning of fiscal year 2013, the Company determined that certain modifications were necessary to present the segment information as now viewed by the Company's chief operating decision maker. While no new reportable segments resulted from the reorganization, certain revenue and expenses previously included in the home robots business unit and the defense and security robots business unit are now combined with other revenue and expenses and presented separately from the two reportable segments.
	Home Robots
	The Company’s home robots business unit offers products to consumers through a network of retail businesses throughout the United States, to various countries through international distributors and retailers, and through the Company’s on-line store. The Company’s home robots business unit includes mobile robots used in the maintenance of households.
	Defense and Security
	The Company’s defense and security robots business unit offers products to the U.S. Department of Defense through a small U.S. government-focused sales force, and to other North American and international entities through small domestic and international sales teams, as well as through North American and international distributors. The Company’s defense and security robots are used to increase warfighters', law enforcement, security forces and first responders' safety and productivity.
	Other
	The Company’s other revenue and cost of revenue result from other smaller business units that do not meet the criteria of a reportable segment, as well as certain operational costs included in cost of revenue.
	The table below presents segment information about revenue, cost of revenue, gross margin and income before income taxes:
		Three Months Ended						Nine Months Ended
		(In thousands)
		September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
	Revenue:
	Home Robots	$	111,363		$	96,291		$	319,590		$	273,887
	Defense & Security	10,094			27,832			33,664			55,217
	Other	3,044			2,175			7,804			6,446
	Total revenue	124,501			126,298			361,058			335,550
	Cost of revenue:
	Home Robots	58,300			45,983			162,411			134,276
	Defense & Security	5,981			14,802			18,348			31,862
	Other	6,159			7,037			18,106			19,568
	Total cost of revenue	70,440			67,822			198,865			185,706
	Gross margin:
	Home Robots	53,063			50,308			157,179			139,611
	Defense & Security	4,113			13,030			15,316			23,355
	Other	(3,115		)	(4,862		)	(10,302		)	(13,122		)
	Total gross margin	54,061			58,476			162,193			149,844
	Research and development	15,212			13,040			45,617			41,722
	Selling and marketing	16,317			11,376			49,323			41,685
	General and administrative	11,495			11,326			39,348			32,390
	Other income (expense), net	152			197			(49		)	477
	Income before income taxes	$	11,189		$	22,931		$	27,856		$	34,524
	Geographic Information
	For the three months ended September 28, 2013 and September 29, 2012, sales to non-U.S. customers accounted for 66.2% and 51.9% of total revenue, respectively, and sales to non-U.S. customers for the nine months ended September 28, 2013 and September 29, 2012 accounted for 61.9% and 59.1% of total revenue, respectively.
	Significant Customers
	For the three months ended September 28, 2013 and September 29, 2012, U.S. federal government orders, contracts and subcontracts accounted for 2.0% and 21.5% of total revenue, respectively, and for the nine months ended September 28, 2013 and September 29, 2012, U.S. federal government orders, contracts and subcontracts accounted for 5.7% and 15.1% of total revenue, respectively.
	For the three months ended September 28, 2013, the Company generated 18.2% and 17.1%, respectively, of total revenue from two of its international distributors of home robots products, and 10.6% of total revenue from one of its domestic customers of home robots products. For the three months ended September 29, 2012, the Company generated 16.6% and 8.9%, respectively, of total revenue from two of its international distributors of home robots products.
	For the nine months ended September 28, 2013, the Company generated 21.6% and 13.3%, respectively, of total revenue from two of its international distributors of home robots products. For the nine months ended September 29, 2012, the Company generated 16.9% and 14.2%, respectively, of total revenue from two of its international distributors of home robots products. For the nine months ended September 28, 2013, none of the Company’s domestic home robots customers accounted for more than 10% of the Company’s total revenue.

Goodwill_Other_Intangible_Asse

Goodwill, Other Intangible Assets and Other Assets	9 Months Ended
	Sep. 28, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	'
	Other Assets
	Other assets at September 28, 2013 and December 29, 2012 consisted of the following:
		September 28,		December 29,
		2013		2012
		(In thousands)
	Investment in Advanced Scientific Concepts, Inc.	$	2,500	$	2,500
	Investment in InTouch Technologies, Inc.	8,001		6,000
		$	10,501	$	8,500
	These investments are accounted utilizing the cost method of accounting. The Company regularly monitors the investments to determine if facts and circumstances have changed in a manner that would require a change in accounting methodology. Additionally, the Company periodically evaluates whether or not an investment has been impaired by considering such factors as economic environment, market conditions, operational performance and other specific factors relating to the business underlying the investment. If any such impairment is identified, a reduction in the carrying value of the investment would be recorded at that time.
Schedule of Cost Method Investments [Table Text Block]	'
	Other assets at September 28, 2013 and December 29, 2012 consisted of the following:
		September 28,		December 29,
		2013		2012
		(In thousands)
	Investment in Advanced Scientific Concepts, Inc.	$	2,500	$	2,500
	Investment in InTouch Technologies, Inc.	8,001		6,000
		$	10,501	$	8,500
Goodwill, Other Intangible Assets and Other Assets	'
	9. Goodwill, Other Intangible Assets and Other Assets
	Goodwill
	The carrying amount of the Company's goodwill at September 28, 2013 is $48.8 million, of which $41.1 million resulted from the acquisition of Evolution Robotics, Inc. in October 2012 and was assigned to the home robots reporting unit. $7.7 million (net of a subsequent write-down of $0.2 million) resulted from the acquisition of Nekton Research, LLC completed in September 2008 and was assigned to the defense and security reporting unit. In conjunction with the reorganization completed as of the beginning of the fiscal year 2013, the defense and security reporting unit was divided into two reporting units: the defense and security reporting unit and the research reporting unit. As a result, the goodwill of $7.9 million was reassigned utilizing a relative fair value allocation approach. $7.7 million and $0.2 million were reassigned to the defense and security and research reporting units, respectively.
	During the three month period ended June 29, 2013, the Company decided to refocus its funded research activities. The Company considered this decision to be an impairment indicator, requiring an interim impairment test within the research reporting unit. The Company performed an impairment assessment using the income approach, and determined that goodwill was impaired. The Company recorded an impairment loss of $0.2 million within general and administrative expenses during the three months ended June 29, 2013.
	Other Intangible Assets
	Other intangible assets include the value assigned to completed technology, research contracts, and a trade name. The estimated useful lives for all of these intangible assets are two to ten years. The intangible assets are being amortized on a straight-line basis, which is consistent with the pattern that the economic benefits of the intangible assets are expected to be utilized.
	Intangible assets at September 28, 2013 and December 29, 2012 consisted of the following:
		September 28, 2013								December 29, 2012
		Cost		Accumulated		Impairment Loss		Net		Cost		Accumulated		Net
				Amortization								Amortization
		(In thousands)
	Completed technology	$	30,600	$	5,291	$	1,788	$	23,521	$	30,600	$	2,468	$	28,132
	Research contracts	100		100		—		—		100		100		—
	Tradename	800		734		—		66		800		708		92
	Total	$	31,500	$	6,125	$	1,788	$	23,587	$	31,500	$	3,276	$	28,224
	As part of the Company's decision during the three month period ended June 29, 2013 to refocus its funded research activities, the Company decided to no longer pursue certain research contracts in which completed technology acquired as part of the acquisition of Nekton Research, LLC was utilized. As a result, the Company performed an impairment assessment of the associated intangible asset using the income approach, and recorded an impairment loss of $1.8 million within general and administrative expenses in the three month period ended June 29, 2013.
	Amortization expense related to acquired intangible assets was $919,000 and $92,500 for the three months ended September 28, 2013 and September 29, 2012, respectively. Amortization expense related to acquired intangible assets was $2.8 million and $277,500 for the nine months ended September 28, 2013 and September 29, 2012, respectively. The estimated future amortization expense is expected to be as follows:
		(In thousands)
	Remainder of 2013	$	919
	2014	3,522
	2015	3,482
	2016	3,457
	2017	3,457
	Thereafter	8,750
	Total	$	23,587

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended	9 Months Ended
	Sep. 28, 2013	Sep. 28, 2013
Accounting Policies [Abstract]	'	'
Fair Value Measurement, Policy [Policy Text Block]	'	'
		Fair Value Measurements
		The authoritative guidance for fair value establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
		Financial Assets
		The Company’s financial assets measured at fair value on a recurring basis at September 28, 2013, were as follows:
			Fair Value Measurements as of
			28-Sep-13
			Level 1		Level 2		Level 3
			(In thousands)
		Description
		Assets:
		Money market funds	$	83,822	$	—	$	—
		Corporate and government bonds	—		16,948		—
		Total assets measured at fair value	$	83,822	$	16,948	$	—
		The Company’s financial assets measured at fair value on a recurring basis at December 29, 2012, were as follows:
			Fair Value Measurements as of
			29-Dec-12
			Level 1		Level 2		Level 3
			(In thousands)
		Description
		Assets:
		Money market funds	$	88,144	$	—	$	—
		Corporate bonds	—		12,430		—
		Total assets measured at fair value	$	88,144	$	12,430	$	—
		In each table above, the bond investments are valued based on observable market values as of the Company’s reporting date and are included in Level 2. The bond investments are recorded at fair value and marked-to-market at the end of each reporting period. The realized and unrealized gains and losses are included in comprehensive income for that period. The fair value of the Company’s bond investment is included in short term investments in its consolidated balance sheet.
Basis of Presentation	'	'
		Basis of Presentation
		The accompanying consolidated financial statements include those of iRobot and its subsidiaries, after elimination of all intercompany accounts and transactions. iRobot has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America.
		The accompanying unaudited financial data as of September 28, 2013 and for the three and nine months ended September 28, 2013 and September 29, 2012 has been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. The year-end balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in its Annual Report on Form 10-K for the fiscal year ended December 29, 2012, filed with the SEC on February 15, 2013.
		In the opinion of management, all adjustments necessary to state fairly its statement of financial position as of September 28, 2013 and results of operations and cash flows for the periods ended September 28, 2013 and September 29, 2012 have been made. The results of operations and cash flows for any interim period are not necessarily indicative of the operating results and cash flows for the full fiscal year or any future periods.
Reorganization	'	'
		Reorganization
		In fiscal year 2012, the Company initiated a reorganization that resulted in, among other things, the centralization of all of the Company's engineering and operations activities. This reorganization was completed at the beginning of fiscal year 2013. In conjunction with this reorganization, the Company reviewed the financial statement classification of its costs and expenses. As a result of this review, the Company decided to classify certain expenses differently than had been classified and presented in prior periods to provide a more clear understanding of the Company's financial performance. As part of this review, the Company also evaluated the impact of the reorganization on its segment reporting and determined that certain modifications were necessary to present the segment information as now viewed by the Company's chief operating decision maker. Although the classification of certain expenses on the income statement has changed in fiscal year 2013 as compared to prior periods, the Company recast the financial results of prior periods in a manner consistent with the fiscal year 2013 presentation for comparability purposes. The reclassified amounts reflected in the consolidated statements of income for the three and nine months ended September 29, 2012 included herein conform to the fiscal year 2013 presentation. This reclassification of costs and expenses did not impact previously reported net income or earnings per share as the changes only impacted the categorization of costs within the consolidated statements of income for the periods in question. Consequently, the classification changes did not impact previously presented consolidated balance sheets, statements of cash flow or statements of stockholders' equity.
Revision of Consolidated Balance Sheet as of December 29, 2012	'	'
		Revision of Consolidated Balance Sheet as of December 29, 2012
		During the three month period ended March 30, 2013, the Company identified a classification error related to its reserves for uncertain tax positions on its December 29, 2012 consolidated balance sheet. The Company had recorded a gross income tax receivable in current assets and a gross uncertain tax positions liability against that receivable in current liabilities as of December 29, 2012. In addition, the Company misclassified certain liabilities for uncertain tax positions in current and long-term liabilities. The impact of the errors on the December 29, 2012 consolidated balance sheet was a decrease in Other Current Assets of $2.7 million, an increase in Other Assets of $0.2 million, a decrease in Accrued Expenses of $2.9 million, and an increase in Long-term Liabilities of $0.4 million. These adjustments were not considered to be material, individually or in the aggregate, to previously issued financial statements. The Company has revised its December 29, 2012 consolidated balance sheet to correct these errors as reflected herein. This revision had no impact on the consolidated statement of income, the consolidated statement of comprehensive income, or total cash flows from operating activities, investing activities, or financing activities.
Accounting Changes and Error Corrections [Text Block]	'Out of Period Adjustment During the third quarter of 2013, the Company identified an immaterial error to previously reported depreciation expense due to the use of an incorrect useful life on a leasehold improvement asset. The recorded out of period adjustment to cost of revenue and operating expenses resulted in a $0.6 million increase in third quarter 2013 net income. The adjustment did not have a material impact on the reported financial position or results of operations for the quarter ended September 28, 2013. Additionally, had this adjustment been recorded in the prior periods to which it relates (fiscal 2011, 2012 and the six month period ended June 29, 2013), the impact would not have been material to the reported financial position or results of operations for those periods.	'
Use of Estimates	'	'
		Use of Estimates
		The preparation of these financial statements in conformity with accounting principles generally accepted in the United States requires the Company to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and disclosure of contingent assets and liabilities. On an ongoing basis, management evaluates these estimates and judgments, including those related to revenue recognition, sales returns, bad debts, warranty claims, inventory reserves, valuation of investments, assumptions used in valuing stock-based compensation instruments and income taxes. The Company bases these estimates on historical and anticipated results and trends and on various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. By their nature, estimates are subject to an inherent degree of uncertainty. Actual results may differ from the Company’s estimates.
Fiscal Year-End	'	'
		Fiscal Year-End
		The Company operates and reports using a 52-53 week fiscal year ending on the Saturday closest to December 31. Accordingly, the Company’s fiscal quarters end on the Saturday that falls closest to the last day of the third month of each quarter.
Revenue Recognition	'	'
		Revenue Recognition
		The Company derives its revenue from product sales and, to a lesser extent, government research and development contracts, and commercial research and development contracts. The Company sells products directly to customers and indirectly through resellers and distributors. The Company recognizes revenue from sales of robots under the terms of the customer agreement upon transfer of title and risk of loss to the customer, net of estimated returns, provided that collection is determined to be reasonably assured and no significant obligations remain. Sales to domestic resellers of home robots are typically subject to agreements allowing for limited rights of return, rebates and price protection. Accordingly, the Company reduces revenue for its estimates of liabilities for these rights of return at the time the related sale is recorded. The Company makes an estimate of sales returns for products sold by domestic resellers directly based on historical returns experience and other relevant data. The Company’s international distributor agreements do not currently allow for product returns and, as a result, no reserve for returns is established for this group of customers. The Company has aggregated and analyzed historical returns from domestic resellers and end users which form the basis of its estimate of future sales returns by resellers or end users. When a right of return exists, the provision for these estimated returns is recorded as a reduction of revenue at the time that the related revenue is recorded. If actual returns differ significantly from its estimates, such differences could have a material impact on the Company’s results of operations for the period in which the returns become known. The estimates for returns are adjusted periodically based upon historical rates of returns. The estimates and reserve for rebates and price protection are based on specific programs, expected usage and historical experience. Actual results could differ from these estimates.
		Under cost-plus-fixed-fee (“CPFF”) type contracts, the Company recognizes revenue based on costs incurred plus a pro rata portion of the total fixed fee. Costs incurred include labor and material that are directly associated with individual CPFF contracts plus indirect overhead and general and administrative type costs based upon billing rates submitted by the Company to the Defense Contract Management Agency (“DCMA”). Annually, the Company submits final indirect billing rates to DCMA based upon actual costs incurred throughout the year. In the situation where the Company’s final actual billing rates are greater than the estimated rates currently in effect, the Company records a cumulative revenue adjustment in the period in which the rate differential is collected from the customer. These final billing rates are subject to audit by the Defense Contract Audit Agency (“DCAA”), which can occur several years after the final billing rates are submitted and may result in material adjustments to revenue recognized based on estimated final billing rates. As of September 28, 2013, fiscal year 2007 is under audit by DCAA, and fiscal years 2008 through 2012 are open for audit by DCAA. In the situation where the Company’s anticipated actual billing rates will be lower than the provisional rates currently in effect, the Company records a cumulative revenue adjustment in the period in which the rate differential is identified. Revenue on firm fixed price (“FFP”) contracts is recognized using the percentage-of-completion method. For government product FFP contracts, revenue is recognized as the product is shipped or in accordance with the contract terms. Costs and estimated gross margins on contracts are recorded as revenue as work is performed based on the percentage that incurred costs compare to estimated total costs utilizing the most recent estimates of costs and funding. Changes in job performance, job conditions, and estimated profitability, including those arising from final contract settlements and government audits, may result in revisions to costs and income and are recognized in the period in which the revisions are determined. Since many contracts extend over a long period of time, revisions in cost and funding estimates during the progress of work have the effect of adjusting earnings applicable to past performance in the current period. When the current contract estimate indicates a loss, a provision is made for the total anticipated loss in the current period. Revenue earned in excess of billings, if any, is recorded as unbilled revenue. Billings in excess of revenue earned, if any, are recorded as deferred revenue.
Accounting for Share-Based Payments	'	'
		Accounting for Share-Based Payments
		The Company accounts for share-based payments to employees, including grants of employee stock options and awards in the form of restricted shares and restricted stock units by establishing the fair value of each option grant using the Black-Scholes option pricing model and the fair value of awards based on stock price at the time of grant. The fair value of share-based payments is recorded by the Company as a charge against earnings. The Company recognizes share-based payment expense over the requisite service period of the underlying grants and awards. The Company’s share-based payment awards are accounted for as equity instruments.
Net Income Per Share	'	'
		Net Income Per Share
		The following table presents the calculation of both basic and diluted net income per share:
			Three Months Ended				Nine Months Ended
			(In thousands, except per share amounts)
			28-Sep-13		29-Sep-12		28-Sep-13		29-Sep-12
		Net income	$	7,804	$	15,207	$	24,453	$	23,235
		Weighted-average shares outstanding	28,733		27,650		28,359		27,520
		Dilutive effect of employee stock options and restricted shares	849		671		848		803
		Diluted weighted-average shares outstanding	29,582		28,321		29,207		28,323
		Basic income per share	$	0.27	$	0.55	$	0.86	$	0.84
		Diluted income per share	$	0.26	$	0.54	$	0.84	$	0.82
		Restricted stock units and stock options representing approximately 0.1 million and 0.9 million shares of common stock for the three month periods ended September 28, 2013 and September 29, 2012, respectively, and approximately 0.7 million and 0.7 million shares of common stock for the nine month periods ended September 28, 2013 and September 29, 2012, respectively, were excluded from the computation of diluted earnings per share for these periods because their effect would have been antidilutive.
Income Taxes	'	'
		Income Taxes
		The Company is subject to taxation in the United States and various states and foreign jurisdictions. The statute of limitations for examination by the Internal Revenue Service ("IRS") is closed for fiscal years prior to 2010. During the nine month period ended September 28, 2013, the IRS completed its examination of the Company's tax returns for the years 2008, 2009 and 2010. The statute of limitations for examination by state tax authorities is closed for fiscal years prior to 2009. Federal carryforward attributes that were generated prior to fiscal year 2010, and state carryforward attributes that were generated prior to fiscal year 2009 may still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in a period for which the statute of limitations is still open.
		Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.
		The Company monitors the realization of its deferred tax assets based on changes in facts and circumstances, for example recurring periods of income for tax purposes following historical periods of cumulative losses or changes in tax laws or regulations. The Company's income tax provisions and its assessment of the ability to realize its deferred tax assets involve significant judgments and estimates.
		The Company recorded a tax provision of $3.4 million and $7.7 million for the three month periods ended September 28, 2013 and September 29, 2012, respectively. The $3.4 million provision for the three month period ended September 28, 2013 resulted in an effective income tax rate of 30.3%. The $7.7 million provision for the three month period ended September 29, 2012 resulted in an effective income tax rate of 33.7%. The decrease in the effective income tax rate from 33.7% for the three month period ended September 29, 2012 to 30.3% for the three month period ended September 28, 2013 was primarily due to the inclusion of the federal research and development tax credit in the 2013 income tax provision, which was not enacted into law for inclusion in the 2012 income tax provision.
		The Company recorded a tax provision of $3.4 million and $11.3 million for the nine month periods ended September 28, 2013 and September 29, 2012, respectively. The $3.4 million provision for the nine month period ended September 28, 2013 resulted in an effective tax rate of 12.2%. The $11.3 million provision for the nine month period ended September 29, 2012 resulted in an effective tax rate of 32.7%. The decrease in the effective income tax rate from 32.7% for the nine month period ended September 29, 2012 to 12.2% for the nine month period ended September 28, 2013 was primarily due to the release of $2.7 million of certain income tax reserves due to favorable conclusions of the IRS examination of the Company's income tax returns for the years 2008, 2009 and 2010, the inclusion of the federal research and development tax credit in the 2013 income tax provision, which was not enacted into law for inclusion in the 2012 income tax provision, and the retroactive reinstatement of federal research and development tax credits in 2013. In January 2013, legislation was enacted that included the extension of the federal research and development tax credits. The legislation retroactively reinstated research and development tax credits for 2012 and extended them through December 31, 2013. As a result, the Company recorded a discrete benefit of $1.7 million related to 2012 during the nine month period ended September 28, 2013.
		The Company anticipates the settlement of state tax audits may be finalized within the next twelve months and could result in a decrease in its unrecognized gross tax benefits of up to $0.7 million.
		In September 2013, the U.S. Department of the Treasury and the IRS issued final regulations addressing the acquisition, production and improvement of tangible property, and also proposed regulations addressing the disposition of property.  These regulations replace previously issued temporary regulations and are effective for tax years beginning January 1, 2014, with optional adoption permitted in 2013.  The Company is in the process of analyzing the impact of these new regulations but does not believe they will have a material impact on the Company's consolidated financial statements.
Goodwill	'	'
		Goodwill
		Goodwill is recorded as the difference, if any, between the aggregate consideration paid for an acquisition and the fair value of the net tangible and intangible assets acquired. The Company evaluates goodwill for impairment at the reporting unit level (operating segment or one level below an operating segment) annually or more frequently if the Company believes indicators of impairment exist. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then a two-step goodwill impairment test is performed. The first step of the impairment test involves comparing the fair values of the applicable reporting units with their aggregate carrying values, including goodwill. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, the Company performs the second step of the goodwill impairment test to determine the amount of impairment loss. The second step of the goodwill impairment test involves comparing the implied fair value of the affected reporting unit’s goodwill with the carrying value of that goodwill.
Recent Accounting Pronouncements	'	'
		Recent Accounting Pronouncements
		In July 2013, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update related to the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  This new guidance clarifies guidance and eliminates diversity in practice on the presentation of unrecognized tax benefits when certain situations exist at the reporting date.  This new guidance is effective for annual reporting periods beginning on or after December 15, 2013 and subsequent interim periods.  We are currently assessing the impact, if any, on our consolidated financial statements.
		In February 2013, the FASB issued guidance requiring disclosure of amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present either on the face of the statement of operations or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For amounts not reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. This guidance was effective prospectively for the Company for annual and interim periods beginning January 1, 2013. The impact of these amendments on the Company’s consolidated financial statements was not material.
		From time to time, new accounting pronouncements are issued by FASB that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that recently issued standards, which are not yet effective, will not have a material impact on the Company’s consolidated financial statements upon adoption.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 28, 2013
Accounting Policies [Abstract]	'
Basic and Diluted Net Income Per Share	'
	The following table presents the calculation of both basic and diluted net income per share:
		Three Months Ended				Nine Months Ended
		(In thousands, except per share amounts)
		28-Sep-13		29-Sep-12		28-Sep-13		29-Sep-12
	Net income	$	7,804	$	15,207	$	24,453	$	23,235
	Weighted-average shares outstanding	28,733		27,650		28,359		27,520
	Dilutive effect of employee stock options and restricted shares	849		671		848		803
	Diluted weighted-average shares outstanding	29,582		28,321		29,207		28,323
	Basic income per share	$	0.27	$	0.55	$	0.86	$	0.84
	Diluted income per share	$	0.26	$	0.54	$	0.84	$	0.82
Fair Value Assets Measured on Recurring Basis	'
	The Company’s financial assets measured at fair value on a recurring basis at September 28, 2013, were as follows:
		Fair Value Measurements as of
		28-Sep-13
		Level 1		Level 2		Level 3
		(In thousands)
	Description
	Assets:
	Money market funds	$	83,822	$	—	$	—
	Corporate and government bonds	—		16,948		—
	Total assets measured at fair value	$	83,822	$	16,948	$	—
	The Company’s financial assets measured at fair value on a recurring basis at December 29, 2012, were as follows:
		Fair Value Measurements as of
		29-Dec-12
		Level 1		Level 2		Level 3
		(In thousands)
	Description
	Assets:
	Money market funds	$	88,144	$	—	$	—
	Corporate bonds	—		12,430		—
	Total assets measured at fair value	$	88,144	$	12,430	$	—
Fair Value Measurements, Nonrecurring [Table Text Block]	'

Inventory_Tables

Inventory (Tables)	9 Months Ended
	Sep. 28, 2013
Inventory Disclosure [Abstract]	'
Components of Inventory	'
	Inventory consists of the following:
		28-Sep-13		29-Dec-12
		(In thousands)
	Raw materials	$	5,754	$	8,849
	Work in process	—		60
	Finished goods	43,099		28,056
		$	48,853	$	36,965

Accrued_Expenses_Tables

Accrued Expenses (Tables)	9 Months Ended
	Sep. 28, 2013
Accrued Liabilities, Current [Abstract]	'
Components of Accrued Expenses	'
	Accrued expenses consist of the following:
		28-Sep-13		29-Dec-12
		(In thousands)
	Accrued warranty	$	6,688	$	6,057
	Accrued rent	731		696
	Accrued sales tax	676		719
	Accrued direct fulfillment costs	396		999
	Accrued sales commissions	261		475
	Accrued accounting fees	170		155
	Accrued other	4,487		4,541
		$	13,409	$	13,642

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 28, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Summary of Future Minimum Rental Payments under Operating Leases	'
	Future minimum rental payments under operating leases were as follows as of September 28, 2013:
		Operating
		Leases
		(In thousands)
	Remainder of 2013	$	842
	2014	3,109
	2015	3,040
	2016	2,747
	2017	2,505
	Thereafter	5,682
	Total minimum lease payments	$	17,925
Activity Related to the Warranty Accrual	'
	Activity related to the warranty accrual was as follows:
		Three Months Ended						Nine Months Ended
		September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
		(In thousands)						(In thousands)
	Balance at beginning of period	$	6,322		$	8,990		$	6,057		$	10,306
	Provision	773			1,080			1,832			1,318
	Warranty usage(1)	(407		)	(524		)	(1,201		)	(2,078		)
	Balance at end of period	$	6,688		$	9,546		$	6,688		$	9,546
	-1	Warranty usage includes the expiration of product warranties unutilized.

Acquisition_of_Evolution_Robot1

Acquisition of Evolution Robotics, Inc. (Tables)	9 Months Ended
	Sep. 28, 2013
Business Combinations [Abstract]	'
Schedule of unaudited pro forma consolidated results of operations	'
	The following unaudited pro forma consolidated results of operations for the three and nine month periods ended September 28, 2013 and September 29, 2012 assume that the acquisition of Evolution occurred as of January 1, 2012.
		Three Months Ended				Nine Months Ended
		September 28, 2013		September 29, 2012		September 28, 2013		September 29, 2012
		(In thousands)				(In thousands)
	Revenue	$	124,501	$	131,164	$	361,058	$	344,775
	Net Income	7,804		13,496		24,453		15,703

Industry_Segment_Geographic_In1

Industry Segment, Geographic Information and Significant Customers (Tables)	9 Months Ended
	Sep. 28, 2013
Segment Reporting [Abstract]	'
Segment Information about Revenue, Cost of Revenue, Gross Margin and Income before Income Taxes	'
	The table below presents segment information about revenue, cost of revenue, gross margin and income before income taxes:
		Three Months Ended						Nine Months Ended
		(In thousands)
		September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
	Revenue:
	Home Robots	$	111,363		$	96,291		$	319,590		$	273,887
	Defense & Security	10,094			27,832			33,664			55,217
	Other	3,044			2,175			7,804			6,446
	Total revenue	124,501			126,298			361,058			335,550
	Cost of revenue:
	Home Robots	58,300			45,983			162,411			134,276
	Defense & Security	5,981			14,802			18,348			31,862
	Other	6,159			7,037			18,106			19,568
	Total cost of revenue	70,440			67,822			198,865			185,706
	Gross margin:
	Home Robots	53,063			50,308			157,179			139,611
	Defense & Security	4,113			13,030			15,316			23,355
	Other	(3,115		)	(4,862		)	(10,302		)	(13,122		)
	Total gross margin	54,061			58,476			162,193			149,844
	Research and development	15,212			13,040			45,617			41,722
	Selling and marketing	16,317			11,376			49,323			41,685
	General and administrative	11,495			11,326			39,348			32,390
	Other income (expense), net	152			197			(49		)	477
	Income before income taxes	$	11,189		$	22,931		$	27,856		$	34,524

Goodwill_Other_Intangible_Asse1

Goodwill, Other Intangible Assets and Other Assets (Tables)	9 Months Ended
	Sep. 28, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Cost Method Investments [Table Text Block]	'
	Other assets at September 28, 2013 and December 29, 2012 consisted of the following:
		September 28,		December 29,
		2013		2012
		(In thousands)
	Investment in Advanced Scientific Concepts, Inc.	$	2,500	$	2,500
	Investment in InTouch Technologies, Inc.	8,001		6,000
		$	10,501	$	8,500
Other Intangible Assets	'
	Intangible assets at September 28, 2013 and December 29, 2012 consisted of the following:
		September 28, 2013								December 29, 2012
		Cost		Accumulated		Impairment Loss		Net		Cost		Accumulated		Net
				Amortization								Amortization
		(In thousands)
	Completed technology	$	30,600	$	5,291	$	1,788	$	23,521	$	30,600	$	2,468	$	28,132
	Research contracts	100		100		—		—		100		100		—
	Tradename	800		734		—		66		800		708		92
	Total	$	31,500	$	6,125	$	1,788	$	23,587	$	31,500	$	3,276	$	28,224
Estimated Future Amortization Expense Related to Current Intangible Assets	'
	The estimated future amortization expense is expected to be as follows:
		(In thousands)
	Remainder of 2013	$	919
	2014	3,522
	2015	3,482
	2016	3,457
	2017	3,457
	Thereafter	8,750
	Total	$	23,587

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Revision (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 28, 2013
Quantifying Misstatement in Current Year Financial Statements, Amount	$0.60
Document Period End Date	28-Sep-13
Other Current Assets [Member]	'
Quantifying Misstatement in Current Year Financial Statements, Amount	2.7
Other Assets [Member]	'
Quantifying Misstatement in Current Year Financial Statements, Amount	0.2
Accrued Liabilities [Member]	'
Quantifying Misstatement in Current Year Financial Statements, Amount	2.9
Other Liabilities [Member]	'
Quantifying Misstatement in Current Year Financial Statements, Amount	$0.40

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Basic and Diluted Net Income Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Schedule Of Computation Of Basic And Diluted Earnings Per Common Share [Line Items]	'	'	'	'
Document Period End Date	28-Sep-13	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	100,000	900,000	700,000	700,000
Net income	$7,804	$15,207	$24,453	$23,235
Weighted-average shares outstanding	28,733,000	27,650,000	28,359,000	27,520,000
Dilutive effect of employee stock options and restricted shares	849,000	671,000	848,000	803,000
Diluted weighted-average shares outstanding	29,582,000	28,321,000	29,207,000	28,323,000
Basic income per share	$0.27	$0.55	$0.86	$0.84
Diluted income per share	$0.26	$0.54	$0.84	$0.82

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012	Dec. 29, 2012
Disclosure Summary Of Significant Accounting Policies Additional Information [Abstract]	'	'	'	'	'
Finite-Lived Intangible Assets, Gross	$31,500	'	$31,500	'	$31,500
Finite-Lived Intangible Assets, Net	$23,587	'	$23,587	'	$28,224
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.1	0.9	0.7	0.7	'

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Tax provision	$3,385,000	$7,724,000	$3,403,000	$11,289,000
Effective income tax rate	30.30%	33.70%	12.20%	32.70%
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	'	'	2,700,000	'
Income Tax Reconciliation, Tax Credits, Research	'	'	1,700,000	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$700,000	'	$700,000	'

Summary_of_Significant_Account7

Summary of Significant Accounting Policies - Fair Value Assets Measured on Recurring Basis (Detail) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	$83,822	$88,144
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	83,822	88,144
Fair Value, Inputs, Level 1 [Member] | Corporate bonds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	16,948	12,430
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 2 [Member] | Corporate bonds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	16,948	12,430
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Corporate bonds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Recurring	$0	$0

Summary_of_Significant_Account8

Summary of Significant Accounting Policies - Fair Value Assets Measured on a Nonrecurring Basis (Details) (USD $)	Sep. 28, 2013	Dec. 29, 2012	Sep. 30, 2008
In Thousands, unless otherwise specified			Nekton Research LLC [Member]
			Research Reporting Unit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Goodwill	$48,751	$48,951	$200
Finite-Lived Intangible Assets, Gross	31,500	31,500	'
Finite-Lived Intangible Assets, Net	$23,587	$28,224	'

Summary_of_Significant_Account9

Summary of Significant Accounting Policies - Out of period Adjustments (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 28, 2013
Quantifying Misstatement in Current Year Financial Statements [Line Items]	'
Error Correction, Amount	$0.60

Inventory_Details

Inventory (Details) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Inventory, Raw Materials, Net of Reserves	$5,754	$8,849
Inventory, Work in Process, Net of Reserves	0	60
Inventory, Finished Goods, Net of Reserves	43,099	28,056
Inventory	$48,853	$36,965

Stock_Option_Plans_Additional_

Stock Option Plans - Additional Information (Detail)	0 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended
	Oct. 10, 2005	Sep. 28, 2013	Sep. 28, 2013	Sep. 28, 2013	Sep. 28, 2013	Sep. 28, 2013	Sep. 28, 2013	Oct. 10, 2005
			Stock Options	Stock Options	Stock Options	Restricted stock units	2005 Plan	2005 Plan
				Minimum	Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'
Effective date for stock options plan	10-Oct-05	'	'	'	'	'	'	'
Shares reserved for issuance in different forms	'	'	'	'	'	'	'	1,583,682
Increase in number of shares reserved and available for issuance in different forms	'	4.50%	'	'	'	'	'	'
Share based compensation arrangement shares available for grant	'	'	'	'	'	'	3,872,511	'
Vesting period for options	'	'	'	'0 years	'5 years	'	'	'
Minimum expiration period for options	'	'	'	'7 years	'10 years	'	'	'
Minimum period for expiration of options in case of employee termination	'	'	'60 days	'	'	'	'	'
Maximum period for expiration of options in case of employee termination	'	'	'90 days	'	'	'	'	'
Common stock granted	'	31,600	'	'	'	'	'	'
Restricted stock units granted	'	'	'	'	'	74,490	'	'

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Accounts Payable, Current [Abstract]	'	'
Accrued warranty	$6,688	$6,057
Accrued rent	731	696
Accrued sales tax	676	719
Accrued direct fulfillment costs	396	999
Accrued sales commissions	261	475
Accrued accounting fees	170	155
Accrued other	4,487	4,541
Accrued expenses	$13,409	$13,642

Commitments_and_Contingencies_1

Commitments and Contingencies - Summary of Future Minimum Rental Payments under Operating Leases (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Commitments and Contingencies Disclosure [Abstract]	'	'	'	'
Rental expense under operating leases	$1,100,000	$1,000,000	$3,500,000	$3,200,000
Disclosure Summary Of Future Minimum Rental Payments Under Operating Leases [Abstract]	'	'	'	'
Remainder of 2013	842,000	'	842,000	'
2014	3,109,000	'	3,109,000	'
2015	3,040,000	'	3,040,000	'
2016	2,747,000	'	2,747,000	'
2017	2,505,000	'	2,505,000	'
Thereafter	5,682,000	'	5,682,000	'
Total minimum lease payments	$17,925,000	'	$17,925,000	'

Commitments_and_Contingencies_2

Commitments and Contingencies - Activity Related to Warranty Accrual (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013		Sep. 29, 2012		Sep. 28, 2013	Sep. 29, 2012
Commitments and Contingencies Disclosure [Abstract]	'		'		'	'
Document Period End Date	28-Sep-13		'		'	'
Movement in Standard Product Warranty Accrual [Roll Forward]	'		'		'	'
Balance at beginning of period	$6,322		$8,990		$6,057	$10,306
Provision	773		1,080		1,832	1,318
Warranty usage	-407	[1]	-524	[1]	1,201	2,078
Balance at end of period	$6,688		$9,546		$6,688	$9,546
[1]	Warranty usage includes the expiration of product warranties unutilized.

Acquisition_of_Evolution_Robot2

Acquisition of Evolution Robotics, Inc. (Details) (Evolution Robotics, Inc. (ER), USD $)	0 Months Ended
In Millions, unless otherwise specified	Oct. 02, 2012
Evolution Robotics, Inc. (ER)	'
Business Acquisition, Pro Forma Information [Line Items]	'
Percentage of voting interests acquired	100.00%
Consideration transferred	$74.80
Purchase price deposit in escrow, indemnification for breach	$8.88

Industry_Segment_Geographic_In2

Industry Segment, Geographic Information and Significant Customers - Segment Information about Revenue, Cost of Revenue, Gross Margin and Income before Income Taxes (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013		Sep. 29, 2012
Revenue:	'	'	'		'
Total revenue	$124,501	$126,298	$361,058		$335,550
Cost of revenue:	'	'	'		'
Total cost of revenue	70,440	67,822	198,865		185,706
Gross margin:	'	'	'		'
Gross margin	54,061	58,476	162,193		149,844
Research and development	15,212	13,040	45,617	[1]	41,722	[1]
Selling and marketing	16,317	11,376	49,323	[1]	41,685	[1]
General and administrative	11,495	11,326	39,348	[1]	32,390	[1]
Other income (expense), net	152	197	-49		477
Income before income taxes	11,189	22,931	27,856		34,524
Home Robots	'	'	'		'
Revenue:	'	'	'		'
Total revenue	111,363	96,291	319,590		273,887
Cost of revenue:	'	'	'		'
Total cost of revenue	58,300	45,983	162,411		134,276
Gross margin:	'	'	'		'
Gross margin	53,063	50,308	157,179		139,611
Defense & Security	'	'	'		'
Revenue:	'	'	'		'
Total revenue	10,094	27,832	33,664		55,217
Cost of revenue:	'	'	'		'
Total cost of revenue	5,981	14,802	18,348		31,862
Gross margin:	'	'	'		'
Gross margin	4,113	13,030	15,316		23,355
Other	'	'	'		'
Revenue:	'	'	'		'
Total revenue	3,044	2,175	7,804		6,446
Cost of revenue:	'	'	'		'
Total cost of revenue	6,159	7,037	18,106		19,568
Gross margin:	'	'	'		'
Gross margin	($3,115)	($4,862)	($10,302)		($13,122)
[1]	Total stock-based compensation recorded in the three and nine months ended SeptemberB 28, 2013 and SeptemberB 29, 2012 included in the above figures breaks down by expense classification as follows:B Three Months EndedB Nine Months EndedB SeptemberB 28, 2013B SeptemberB 29, 2012B SeptemberB 28, 2013B SeptemberB 29, 2012Cost of product revenue$250B $289B $496B $715Research and development669B 365B 1,963B 1,271Selling and marketing348B 158B 832B 574General and administrative2,210B 1,796B 6,378B 5,463

Industry_Segment_Geographic_In3

Industry Segment, Geographic Information and Significant Customers - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Number of operating segments	'	'	2	'
Number of customer generating major revenues	'	'	2	'
Customer Concentration Risk [Member] | Government Contracts Concentration Risk [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Concentration Risk, Percentage	2.00%	21.50%	5.70%	15.10%
Customer Concentration Risk [Member] | Customer Concentration Risk [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Concentration Risk, Percentage	66.20%	51.90%	61.90%	59.10%
Customer Concentration Risk [Member] | International distributors of home robots products | Distributor One	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Concentration Risk, Percentage	18.20%	16.60%	21.60%	16.90%
Customer Concentration Risk [Member] | International distributors of home robots products | Distributor Two	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Concentration Risk, Percentage	17.10%	8.90%	13.30%	14.20%
Customer Concentration Risk [Member] | Customer Concentration Risk [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Concentration Risk, Percentage	10.60%	'	'	'

Goodwill_Other_Intangible_Asse2

Goodwill, Other Intangible Assets and Other Assets - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

Sep. 28, 2013

Sep. 29, 2012

Sep. 28, 2013

Sep. 29, 2012

Dec. 29, 2012

Sep. 28, 2013

Sep. 28, 2013

Oct. 30, 2012

Sep. 30, 2008

Sep. 30, 2008

Sep. 28, 2013

Sep. 30, 2008

Minimum

Maximum

Home Robots

Defense & Security

Defense and Security Reporting Unit

Research Reporting Unit [Member]

Research Reporting Unit [Member]

Evolution Robotics, Inc. (ER)

Nekton Research LLC [Member]

Nekton Research LLC [Member]

Nekton Research LLC [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill

$48,751,000

'

$48,751,000

'

$48,951,000

'

'

$41,100,000

$7,700,000

$7,700,000

'

$200,000

Goodwill, Impairment Loss

'

'

'

'

'

'

'

'

'

'

200,000

'

Goodwill, Gross

'

'

'

'

'

'

'

'

7,900,000

'

'

'

Estimated useful life of intangible assets

'

'

'

'

'

'2 years

'10 years

'

'

'

'

'

Amortization of Acquired Intangible Assets

$919,000

$92,500

$2,800,000

$277,500

'

'

'

'

'

'

'

'

Goodwill_Other_Intangible_Asse3

Goodwill, Other Intangible Assets and Other Assets - Other Intangible Assets (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012	Dec. 29, 2012
Finite-Lived Intangible Assets [Line Items]	'	'	'	'	'
Impairment of Intangible Assets, Finite-lived	$1,800,000	'	'	'	'
Finite-Lived Intangible Assets, Gross	31,500,000	'	31,500,000	'	31,500,000
Intangible assets accumulated amortization	6,125,000	'	6,125,000	'	3,276,000
Finite-lived intangible assets, accumulated impairment loss	1,788,000	'	1,788,000	'	'
Intangible Assets, Net	23,587,000	'	23,587,000	'	28,224,000
Amortization of Acquired Intangible Assets	919,000	92,500	2,800,000	277,500	'
Completed technology	'	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'	'
Finite-Lived Intangible Assets, Gross	30,600,000	'	30,600,000	'	30,600,000
Intangible assets accumulated amortization	5,291,000	'	5,291,000	'	2,468,000
Finite-lived intangible assets, accumulated impairment loss	1,788,000	'	1,788,000	'	'
Intangible Assets, Net	23,521,000	'	23,521,000	'	28,132,000
Research contracts	'	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'	'
Finite-Lived Intangible Assets, Gross	100,000	'	100,000	'	100,000
Intangible assets accumulated amortization	100,000	'	100,000	'	100,000
Finite-lived intangible assets, accumulated impairment loss	0	'	0	'	'
Intangible Assets, Net	0	'	0	'	0
Trade Names	'	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'	'
Finite-Lived Intangible Assets, Gross	800,000	'	800,000	'	800,000
Intangible assets accumulated amortization	734,000	'	734,000	'	708,000
Finite-lived intangible assets, accumulated impairment loss	0	'	0	'	'
Intangible Assets, Net	$66,000	'	$66,000	'	$92,000

Goodwill_Other_Intangible_Asse4

Goodwill, Other Intangible Assets and Other Assets - Estimated Future Amortization Expense Related to Current Intangible Assets (Detail) (USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Disclosure Estimated Future Amortization Expense Related To Current Intangible Assets [Abstract]	'	'
Remainder of 2013	$919	'
2014	3,522	'
2015	3,482	'
2016	3,457	'
2017	3,457	'
Thereafter	8,750	'
Intangible Assets, Net	$23,587	$28,224

Goodwill_Other_Intangible_Asse5

Goodwill, Other Intangible Assets and Other Assets - Other Assets (Details) (Preferred Stock [Member], USD $)	Sep. 28, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Schedule of Cost-method Investments [Line Items]	'	'
Cost Method Investments	$10,501	$8,500
Advanced Scientific Concepts, Inc. [Member]	'	'
Schedule of Cost-method Investments [Line Items]	'	'
Cost Method Investments	2,500	2,500
InTouch Technologies, Inc. [Member]	'	'
Schedule of Cost-method Investments [Line Items]	'	'
Cost Method Investments	$8,001	$6,000