iRobot (IRBT) 10-K 16 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 30, 2017	Feb. 12, 2018	Jul. 01, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	IROBOT CORP
Entity Central Index Key	1,159,167
Document Type	10-K
Document Period End Date	Dec. 30, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2,300,000,000
Entity Common Stock, Shares Outstanding		27,945,275

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 128,635	$ 214,523
Short term investments	37,225	39,930
Accounts receivable, net	142,829	73,048
Inventory	106,932	50,578
Other current assets	19,105	5,591
Total current assets	434,726	383,670
Property and equipment, net	44,579	27,532
Deferred tax assets	31,531	30,585
Goodwill	121,440	41,041
Intangible assets, net	44,712	12,207
Other assets	14,534	12,877
Total assets	691,522	507,912
Current liabilities:
Accounts payable	116,316	67,281
Accrued expenses	73,647	40,869
Deferred revenue and customer advances	7,761	4,486
Total current liabilities	197,724	112,636
Deferred tax liabilities	9,539	0
Other long term liabilities	13,932	6,320
Total long term liabilities	23,471	6,320
Total liabilities	221,195	118,956
Commitments and contingencies (Note 14):
Preferred stock, 5,000,000 shares authorized and none outstanding	0	0
Common stock, $0.01 par value, 100,000,000 shares authorized; 27,945,144 and 27,237,870 shares issued and outstanding at December 30, 2017 and December 31, 2016, respectively	279	272
Additional paid-in capital	190,067	161,885
Retained earnings	277,989	226,950
Accumulated other comprehensive income (loss)	1,992	(151)
Total stockholders’ equity	470,327	388,956
Total liabilities and stockholders’ equity	$ 691,522	$ 507,912

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	27,945,144	27,237,870
Common stock, shares outstanding	27,945,144	27,237,870

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Revenue		$ 883,911	$ 660,604	$ 616,778
Cost of product revenue		438,114	337,832	325,295
Amortization of intangible assets		12,638	3,457	2,557
Total cost of revenue	[1]	450,752	341,289	327,852
Gross margin		433,159	319,315	288,926
Operating expenses:
Research and development	[1]	113,149	79,805	76,071
Selling and marketing	[1]	162,110	115,125	97,772
General and administrative	[1]	84,771	66,828	53,540
Amortization of intangible assets		439	0	925
Total operating expenses		360,469	261,758	228,308
Operating income		72,690	57,557	60,618
Other income, net		3,676	3,804	2,353
Income before income taxes		76,366	61,361	62,971
Income tax expense		25,402	19,422	18,841
Net income		$ 50,964	$ 41,939	$ 44,130
Net income per share
Basic income per share (in dollars per share)		$ 1.85	$ 1.51	$ 1.49
Diluted earnings per share (in dollars per share)		$ 1.77	$ 1.48	$ 1.47
Number of weighted average common shares used in calculations per share
Basic (In shares)		27,611	27,698	29,550
Diluted (In shares)		28,753	28,292	30,107
Stock-based compensation recorded breaks down by expense classification as follows:
Stock-based compensation		$ 19,751	$ 15,995	$ 14,183
Cost of revenue
Stock-based compensation recorded breaks down by expense classification as follows:
Stock-based compensation		1,082	760	1,076
Research and development
Stock-based compensation recorded breaks down by expense classification as follows:
Stock-based compensation		5,009	3,646	3,256
Selling and marketing
Stock-based compensation recorded breaks down by expense classification as follows:
Stock-based compensation		2,571	2,008	1,457
General and administrative
Stock-based compensation recorded breaks down by expense classification as follows:
Stock-based compensation		$ 11,089	$ 9,581	$ 8,394
[1]	Stock-based compensation recorded in fiscal 2017, 2016 and 2015 breaks down by expense classification as follows: Fiscal Year Ended December 30, 2017 December 31, 2016 January 2, 2016 (In thousands)Cost of revenue$1,082 $760 $1,076Research and development5,009 3,646 3,256Selling and marketing2,571 2,008 1,457General and administrative11,089 9,581 8,394

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 50,964	$ 41,939	$ 44,130
Other comprehensive income (loss):
Net foreign currency translation adjustments	1,994	0	0
Net unrealized gains on cash flow hedges, net of tax	490	0	0
Net gains on cash flow hedge reclassified into earnings, net of tax	(295)
Net unrealized gains (losses) on marketable securities, net of tax	(46)	85	(85)
Total comprehensive income	$ 53,107	$ 42,024	$ 44,045

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Beginning balance, shares at Dec. 27, 2014		29,644,602
Beginning balance at Dec. 27, 2014	$ 390,436,000	$ 297,000	$ 249,409,000	$ 140,881,000	$ (151,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for exercise of stock options (in shares)	390,085	390,085
Issuance of common stock for exercise of stock options	$ 6,464,000	$ 4,000	6,460,000
Vesting of restricted stock units (in shares)	14,610
Vesting of restricted stock units	$ 0
Vesting of restricted stock units (in shares)		340,754
Vesting of restricted stock units	0	$ 3,000	(3,000)
Tax benefit of excess stock based compensation deduction	822,000		822,000
Stock-based compensation	14,183,000		14,183,000
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units (in shares)		(37,969)
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units	(1,295,000)		(1,295,000)
Other comprehensive income (loss)	(85,000)				(85,000)
Directors' deferred compensation	$ 149,000		149,000
Stock repurchases (in shares)	(1,260,276)
Stock repurchases	$ (37,393,000)	$ (13,000)	(37,380,000)
Net income	44,130,000			44,130,000
Ending balance, shares at Jan. 02, 2016		29,091,806
Ending balance at Jan. 02, 2016	$ 417,411,000	$ 291,000	232,345,000	185,011,000	(236,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for exercise of stock options (in shares)	456,498	456,498
Issuance of common stock for exercise of stock options	$ 9,344,000	$ 4,000	9,340,000
Vesting of restricted stock units (in shares)	6,721
Vesting of restricted stock units	$ 0
Vesting of restricted stock units (in shares)		363,643
Vesting of restricted stock units	0	$ 4,000	(4,000)
Tax benefit of excess stock based compensation deduction	2,421,000		2,421,000
Stock-based compensation	15,995,000		15,995,000
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units (in shares)		(39,676)
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units	(1,300,000)		(1,300,000)
Other comprehensive income (loss)	85,000				85,000
Directors' deferred compensation	$ 82,000		82,000
Stock repurchases (in shares)	(2,641,122)
Stock repurchases	$ (97,021,000)	$ (27,000)	(96,994,000)
Net income	$ 41,939,000			41,939,000
Ending balance, shares at Dec. 31, 2016	27,237,870	27,237,870
Ending balance at Dec. 31, 2016	$ 388,956,000	$ 272,000	161,885,000	226,950,000	(151,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of a change in accounting principle related to stock-based compensation	$ 858,000		783,000	75,000
Issuance of common stock for exercise of stock options (in shares)	367,267	367,267
Issuance of common stock for exercise of stock options	$ 10,573,000	$ 4,000	10,569,000
Vesting of restricted stock units (in shares)	14,901
Vesting of restricted stock units	$ 0
Vesting of restricted stock units (in shares)		376,335
Vesting of restricted stock units	0	$ 4,000	(4,000)
Stock-based compensation	19,751,000		19,751,000
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units (in shares)		(51,229)
Stock withheld to cover tax withholdings requirements upon vesting of restricted stock units	(2,983,000)	$ (1,000)	(2,982,000)
Other comprehensive income (loss)	1,948,000				1,948,000
Directors' deferred compensation	65,000		65,000
Unrealized net gain on derivative financial instruments	$ 195,000				195,000
Stock repurchases (in shares)	0
Stock repurchases	$ 0
Net income	$ 50,964,000			50,964,000
Ending balance, shares at Dec. 30, 2017	27,945,144	27,945,144
Ending balance at Dec. 30, 2017	$ 470,327,000	$ 279,000	$ 190,067,000	$ 277,989,000	$ 1,992,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Cash flows from operating activities:
Net income	$ 50,964	$ 41,939	$ 44,130
Adjustments to reconcile net income to net cash provided by operating activities, net of the effects of acquisitions:
Depreciation and amortization	25,499	13,606	15,304
Gain (Loss) on Disposition of Business and Cost Method Investment	1,267	1,067	3,287
(Income) loss on equity method investment	65	(1,376)	0
Impairment on cost method investment	155	0	0
Gain on business acquisition	(2,243)	0	0
Stock-based compensation	19,751	15,995	14,183
Deferred income taxes, net	(999)	3,557	(985)
Tax benefit of excess stock-based compensation deductions	0	(2,971)	(1,467)
Non-cash director deferred compensation	65	82	149
Other	1,846	0	0
Changes in operating assets and liabilities — (use) source
Accounts receivable	(53,251)	25,682	(31,461)
Inventory	(1,470)	(981)	(13,978)
Other assets	(10,562)	3,187	203
Accounts payable	17,457	6,502	3,786
Accrued liabilities	23,447	10,181	(3,251)
Deferred revenue and customer advances	2,149	2,996	(584)
Long term liabilities	4,709	(908)	3,970
Net cash provided by operating activities	76,315	116,424	26,712
Cash flows from investing activities:
Additions of property and equipment	(23,371)	(10,817)	(9,372)
Change in other assets	(1,542)	(2,093)	(1,015)
Proceeds from Divestiture of Business and cost method investment	1,267	24,154	5,645
Cash paid for business acquisitions, net of cash acquired	(148,765)	0	0
Purchases of investments	(10,578)	(16,554)	(17,755)
Sales and maturities of investments	13,066	9,500	20,500
Net cash provided by (used in) investing activities	(169,923)	4,190	(1,997)
Cash flows from financing activities:
Income tax withholding payment associated with restricted stock vesting	(2,983)	(1,300)	(1,295)
Proceeds from stock option exercises	10,573	9,344	6,464
Stock repurchases	0	(97,021)	(37,393)
Tax benefit of excess stock-based compensation deductions	0	2,971	1,467
Net cash provided by (used in) financing activities	7,590	(86,006)	(30,757)
Effect of exchange rate changes on cash and cash equivalents	130	0	0
Net increase (decrease) in cash and cash equivalents	(85,888)	34,608	(6,042)
Cash and cash equivalents, at beginning of period	214,523	179,915	185,957
Cash and cash equivalents, at end of period	128,635	214,523	179,915
Supplemental disclosure of cash flow information
Cash paid for income taxes	25,879	14,061	14,341
Additions of property and equipment included in accounts payable	$ 5,001	$ 1,550	$ 848

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business iRobot Corporation ("iRobot" or the "Company") designs and builds robots that empower people to do more. The Company develops robotic technology and applies it to produce and market consumer robots. The Company’s revenue is primarily generated from product sales.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Foreign Currency Translation The accompanying consolidated financial statements include those of iRobot and its subsidiaries, after elimination of all intercompany balances and transactions. In addition, certain prior year amounts have been reclassified to conform to the current year presentation. iRobot has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP). For the Company's subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated into U.S. dollars at period-end foreign exchange rates. Revenues and expenses are translated into U.S. dollars at the average foreign exchange rates for the period. Translation adjustments are excluded from the determination of net income and are recorded in accumulated other comprehensive income (loss), a separate component of stockholders' equity. Use of Estimates The preparation of these financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenue and expenses and the disclosure of contingent assets and liabilities in the consolidated financial statements. These estimates and judgments, include but are not limited to, revenue recognition (specifically sales returns and other allowances); valuation of goodwill and acquired intangible assets; accounting for business combinations; evaluating loss contingencies; and accounting for income taxes and related valuation allowances. The Company bases these estimates and judgments on historical experience, market participant fair value considerations, projected future cash flows and various other factors that the Company believes are reasonable under the circumstances. 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 primarily derives its revenue from product sales. Until the divestiture of the defense and security business unit in April 2016 (see Note 4), the Company also generated minimal revenue from government 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 and allowances, provided that collection is determined to be reasonably assured and no significant obligations remain. Beginning in the third quarter of 2015, the Company introduced its first connected robot. Each sale of a connected robot represents a multiple-element arrangement containing the robot, an app and potential future unspecified software upgrades. Revenue is allocated to the deliverables based on their relative selling prices which have been determined using best estimate of selling price (BESP), as the Company has not been able to establish vendor specific objective evidence (VSOE) or obtain relevant third party evidence (TPE). Revenue allocated to the app and unspecified software upgrades is then deferred and recognized on a straight-line basis over the period in which the Company expects to provide the upgrades, which is the estimated life of the robot. Sales to retailers of consumer robots are typically subject to agreements allowing for limited rights of return, rebates and price protection. The Company also provides limited rights of returns for direct-to-consumer sales generated through its on-line stores and certain international distributors. Accordingly, the Company reduces revenue for its estimates of liabilities for these rights of return, rebates, and price protection, as well as discounts and promotions, at the time the related sale is recorded. The estimates for rights of return are directly based on specific terms and conditions included in the customer agreements, historical returns experience and various other assumptions that the Company believes are reasonable under the circumstances. In the case of new product introductions, the estimates for returns applied to the new products are based upon the estimates for the most similar predecessor products until such time that the Company has enough actual returns experience for the new products, which is typically two holiday return cycles. At that time, the Company incorporates that data into the development of returns estimates for the new products. The Company updates its analysis of returns on a quarterly basis. If actual returns differ significantly from the Company's estimates, or if modifications to individual customer agreements are entered into that impact their rights of returns, such differences could result in an adjustment to previously established reserves and could have a material impact, either favorably or unfavorably, on the Company’s results of operations for the period in which the actual returns become known or the agreement is modified. In 2016, the Company began selling to one domestic distributor under an agreement that provides product return privileges. As a result, the Company recognizes revenue from sales to this distributor when the product is resold by the distributor. The estimates and adjustments for rebates and price protection are based on specific programs, expected usage and historical experience. Actual results could differ from these estimates. As of December 30, 2017, the Company has reserves for product returns of $42.7 million , discounts and promotions of $58.2 million and price protection of $3.1 million . As of December 31, 2016, the Company had reserves for product returns of $27.7 million , discounts and promotions of $ 22.1 million and price protection of $1.5 million. Prior to the Company's divestiture of the defense and security business unit in April 2016 (see Note 4), the Company generated minimal revenue from government contracts. Under cost-plus-fixed-fee (CPFF) type contracts, the Company recognized revenue based on costs incurred plus a pro rata portion of the total fixed fee. Costs incurred included labor and material that were 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 submitted 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 used, 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 December 30, 2017, fiscal year 2016 is open for audit by DCAA. In the situation where the Company’s anticipated actual billing rates will be lower than the provisional rates used, the Company records a cumulative revenue adjustment in the period in which the rate differential is identified. Revenue on firm fixed price (FFP) contracts was recognized using the percentage-of-completion method. For government product FFP contracts, revenue was recognized as the product was shipped or in accordance with the contract terms. Costs and estimated gross margins on contracts were recorded as revenue as work was performed based on the percentage that incurred costs compared to estimated total costs utilizing the most recent estimates of costs and funding. Revenue earned in excess of billings, if any, was recorded as unbilled revenue. Billings in excess of revenue earned, if any, were recorded as deferred revenue. Business Combinations The Company accounts for transactions that represent business combinations under the acquisition method of accounting. The Company allocates the total consideration paid for each acquisition to the assets it acquires and liabilities it assumes based on their fair values as of the date of acquisition, including identifiable intangible assets. The Company bases the fair value of identifiable intangible assets acquired in a business combination on valuations that use information and assumptions determined by management and which consider management’s best estimates of inputs and assumptions that a market participant would use. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to accurately value assets acquired and liabilities assumed at the business combination date, its estimates and assumptions are inherently uncertain and subject to refinement. As a result, during the measurement period, which is generally one year from the acquisition date, any adjustment to the assets acquired and liabilities assumed is recorded against goodwill in the period in which the amount is determined. Any adjustment identified subsequent to the measurement period is included in operating results in the period in which the amount is determined. Cash and Cash Equivalents The Company considers all highly liquid investments with an original or remaining maturity of three months or less at the time of purchase to be cash equivalents. The Company invests its excess cash primarily in money market funds or savings accounts of major financial institutions. Accordingly, its cash equivalents are subject to minimal credit and market risk. At December 30, 2017 and December 31, 2016 , cash equivalents were comprised of money market funds totaling $3.2 million and $157.0 million , respectively. These cash equivalents are carried at cost, which approximates fair value. Short Term Investments The Company’s investments are classified as available-for-sale and are recorded at fair value with any unrealized gain or loss recorded as an element of stockholders’ equity. The fair value of investments is determined based on quoted market prices at the reporting date for those instruments. As of December 30, 2017 and December 31, 2016 , investments consisted of: December 30, December 31, Cost Fair Cost Fair (In thousands) Corporate and government bonds $ 37,767 $ 37,225 $ 40,439 $ 39,930 Total short term investments $ 37,767 $ 37,225 $ 40,439 $ 39,930 As of December 30, 2017 , the Company’s investments had maturity dates ranging from March 2018 to September 2020. The Company invests primarily in investment grade securities and limits the amount of investment in any single issuer. Accounts receivable allowances Allowance for product returns : The Company records an allowance for product returns for the estimated amount of product that may be returned. The allowance is based on specific terms and conditions included in the customer agreements, historical returns experience and various other assumptions that the Company believes are reasonable under the circumstances. Allowance for discounts and promotions : The Company records an allowance for discounts and promotions related to promotional marketing support, contractual discounts, etc. The allowance is based on specific programs, expected usage and historical experience. Allowance for price protection : The Company records an allowance for price protection for the estimated amount of support expected to be provided to customers for product transitions. The allowance is based on specific programs, expected usage and historical experience. Allowance for doubtful accounts : The Company records an allowance for doubtful accounts for the estimated amount of accounts receivable that may not be collected. The allowance is based on an assessment of customer creditworthiness, historical payment experience and the age of outstanding receivables. Activity related to accounts receivable allowances was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Allowance for product returns Balance at beginning of period $ 27,673 $ 25,992 $ 27,449 Acquired balance 6,088 — — Provision 54,981 33,992 27,432 Deduction (43,831 ) (28,826 ) (21,979 ) Other adjustments (2,218 ) (3,485 ) (6,910 ) Balance at end of period $ 42,693 $ 27,673 $ 25,992 Allowance for discounts and promotions Balance at beginning of period $ 22,108 $ 23,005 $ 10,749 Acquired balance 11,932 — — Provision 107,390 45,869 39,482 Deduction (79,652 ) (46,610 ) (26,587 ) Other adjustments (3,567 ) (156 ) (639 ) Balance at end of period $ 58,211 $ 22,108 $ 23,005 Allowance for price protection Balance at beginning of period $ 1,550 $ — $ — Acquired balance — — — Provision 3,215 1,550 — Deduction (1,617 ) — — Other adjustments — — — Balance at end of period $ 3,148 $ 1,550 $ — Allowance for doubtful accounts Balance at beginning of period $ 29 $ 33 $ 67 Acquired balance 248 — — Provision 1 — — Deduction (2 ) (4 ) (34 ) Other adjustments — — — Balance at end of period $ 276 $ 29 $ 33 Inventory Inventory is stated at the lower of cost or net realizable value with cost being determined using the first-in, first-out (FIFO) method. The Company maintains a reserve for inventory items to provide for an estimated amount of excess or obsolete inventory. Warranty The Company typically provides a one -year warranty (with the exception of European consumer products, which typically have a two -year warranty period) against defects in materials and workmanship and will either repair the goods, provide replacement products at no charge to the customer or refund amounts to the customer for defective products. The Company records estimated warranty costs, based on historical experience by product, at the time revenue is recognized. Actual results could differ from these estimates, which could cause increases or decreases to the warranty reserves in future periods. Property and Equipment Property and equipment are recorded at cost and consist primarily of computer equipment, leasehold improvements, business applications software and machinery. Depreciation is computed using the straight-line method over the estimated useful lives as follows: Estimated Useful Life Computer and research equipment 2-5 years Furniture 5 Machinery 2-5 Tooling 2-5 Business applications software 5-7 Capital leases and leasehold improvements Lesser of economic benefit period or term of lease Expenditures for additions, renewals and betterments of property and equipment are capitalized. Expenditures for repairs and maintenance are charged to expense as incurred. As assets are retired or sold, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Goodwill and Other Long-Lived Assets Goodwill represents the excess of the purchase price in a business combination over the fair value of the net tangible and intangible assets acquired. Goodwill is not amortized but rather is assessed 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. Goodwill impairment, if any, is determined by comparing the reporting unit's fair value to its carrying value. An impairment loss is recognized in an amount equal to the excess of the reporting unit's carrying value over its fair value, up to the amount of goodwill allocated to the reporting unit. The Company completes the annual impairment evaluation during the fourth quarter each year. Other long-lived assets consist principally of completed technology, tradename, customer relationships, reacquired distribution rights and non-competition agreements. Reacquired distribution rights are amortized on an accelerated basis while all other intangible assets are amortized over their respective estimated useful lives on a straight-line basis, consistent with the pattern in which the economic benefits are being utilized. The Company periodically evaluates the recoverability of other long-lived assets whenever events and changes in circumstances, such as reductions in demand or significant economic slowdowns in the industry, indicate that the carrying amount of an asset may not be fully recoverable. When indicators of impairment are present, the carrying values of the asset group are evaluated in relation to the future undiscounted cash flows of the underlying business. The net book value of the underlying asset is adjusted to fair value if the sum of the expected discounted cash flows is less than book value. Fair values are based on estimates of market prices and assumptions concerning the amount and timing of estimated future cash flows and assumed discount rates, reflecting varying degrees of perceived risk. The impairment assessment of goodwill and other long-lived assets involves significant estimates and assumptions, which may be unpredictable and inherently uncertain. These estimates and assumptions include identification of reporting units and asset groups, long-term growth rates, profitability, estimated useful lives, comparable market multiples, and discount rates. Any changes in these assumptions could impact the result of the impairment assessment. Other Assets At December 30, 2017 and December 31, 2016 , other assets consisted primarily of cost and an equity method investment totaling $14.2 million and $12.9 million , respectively. The Company regularly monitors these investments to determine if facts and circumstances have changed in a manner that would require a change in accounting methodology. Additionally, the Company regularly evaluates whether or not these investments have been impaired by considering such factors as economic environment, market conditions, operational performance and other specific factors relating to the businesses underlying the investments. If any such impairment is identified, a reduction in the carrying value of the investments would be recorded at that time. Financial Instruments and Hedging Activities The Company utilizes derivative instruments to hedge specific financial risks including foreign exchange risk. The Company does not engage in speculative hedging activity. In order to account for a derivative instrument as a hedge, specific criteria must be met, including: (i) ensuring at the inception of the hedge that formal documentation exists for both the hedging relationship and the entity’s risk management objective and strategy for undertaking the hedge and (ii) at the inception of the hedge and on an ongoing basis, the hedging relationship is expected to be highly effective in achieving offsetting changes in fair value attributed to the hedged risk during the period that the hedge is designated. Further, an assessment of effectiveness is required whenever financial statements or earnings are reported. Absent meeting these criteria, changes in fair value are recognized in other income, net, in the consolidated statements of income. Once the underlying forecasted transaction is realized, the gain or loss from the derivative designated as a hedge of the transaction is reclassified from accumulated other comprehensive income (loss) to the statement of income, in revenue or cost of revenue. Any ineffective portion of the derivatives designated as cash flow hedges is recognized in current earnings. Fair Value Measurements The Company accounts for certain assets and liabilities at fair value. The fair value is established based on a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: • Level 1 - observable inputs such as quoted prices for identical instruments in active markets; • Level 2 - inputs other than quoted prices in active markets that are either directly or indirectly observable; and • Level 3 - unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Stock-Based Compensation The Company accounts for stock-based compensation through recognition of the fair value of the stock-based compensation as a charge against earnings. The fair value of employee stock options is estimated at the grant date using the Black-Scholes option-pricing model. The fair value for restricted stock awards, time-based restricted stock units and performance-based restricted stock units is based on the closing share price of the Company's common stock on the date of grant. For performance-based restricted stock units, the compensation cost is recognized based on the number of units expected to vest upon the achievement of the performance conditions. The Company recognizes stock-based compensation as expense over the requisite service period. The Company has elected to account for forfeitures as they occur, rather than applying an estimated forfeiture rate, following its adoption of ASU 2016-09 in the first quarter of 2017. Research and Development Costs incurred in the research and development of the Company’s products are expensed as incurred. Internal Use Software The Company capitalizes costs associated with the development and implementation of software for internal use. At December 30, 2017 and December 31, 2016 , the Company had $12.8 million and $9.5 million , respectively, of costs related to enterprise-wide software included in fixed assets. Capitalized costs are being amortized over the assets’ estimated useful lives. The Company has recorded $1.5 million , $0.4 million and $0.7 million of amortization expense for the years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , respectively. Advertising Expense The Company expenses advertising costs as they are incurred. During the years ended December 30, 2017 , December 31, 2016 and January 2, 2016 advertising expense totaled $91.8 million , $64.4 million and $54.7 million , respectively, and are recorded within the selling and marketing expenses line item. Income Taxes Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis using enacted tax rates in effect in the years in which those temporary differences are expected to be recovered or settled in each jurisdiction. A valuation allowance is provided if, based upon the weight of available evidence, it is more likely than not that the related benefits will not be realized. The Company regularly reviews the deferred tax assets for recoverability considering historical profitability, projected future taxable income, future reversals of existing taxable temporary differences, as well as feasible tax planning strategies in each jurisdiction. As of December 30, 2017, the Company recorded a valuation allowance of $0.8 million for certain foreign deferred tax assets for which the Company believes do not meet the "more likely than not" criteria for recognition. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company recognizes interest and penalties, if any, related to unrecognized tax benefits in the income tax provision. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "Act") was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21% for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system and a one-time transition tax on the mandatory deemed repatriation of foreign earnings. We have estimated our provision for income taxes in accordance with the Act and guidance available as of the date of this filing and as a result have recorded a one-time income tax provision of $11.9 million in the fourth quarter of 2017, the period in which the legislation was enacted. The one-time income tax provision includes $8.9 million related to the remeasurement of certain deferred tax assets and liabilities based on the tax rates at which they are expected to reverse in the future. The one-time income tax expense also includes a provisional amount of $3.0 million related to the one-time transition tax on the mandatory deemed repatriation of foreign earnings. On December 22, 2017, Staff Accounting Bulletin No. 118 (SAB 118) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. In accordance with SAB 118, we have determined that the $3.0 million of current income tax provision recorded relating to the transition tax on the mandatory deemed repatriation of foreign earnings was a provisional amount and a reasonable estimate at December 30, 2017. Additional information and analysis is necessary to complete the calculation and accounting relating to the transition tax on the mandatory deemed repatriation of foreign earnings. Any subsequent adjustments to this amount will be recorded to current income tax provision during the measurement period which is not expected to extend beyond one year from the enactment date. Concentration of Credit Risk and Significant Customers Financial instruments which potentially expose the Company to concentrations of credit risk consist of accounts receivable. Management believes its credit policies are prudent and reflect normal industry terms and business risk. At December 30, 2017 , one customer accounted for a total of 11.5% of the Company's accounts receivable balance. At December 31, 2016 , three customers accounted for a total of 43.9% of the Company's accounts receivable balance, each of which was greater than 10% of the balance and two of whom secured their balance with guaranteed letters of credit, which together represents 32.5% of the balance. For the fiscal year ended December 30, 2017 , the Company generated 13.5% of total revenue from one of its retailers (Amazon). For the fiscal year ended December 31, 2016 , the Company generated 12.9% , 12.3% and 10.4% of total revenue from its distributor in Japan, Sales On Demand Corporation (SODC), Robopolis SAS, a network of affiliated European distributors (Robopolis) and Amazon, respectively. For the fiscal year ended January 2, 2016 , the Company generated 13.3% and 12.7% of total revenue from SODC and Robopolis, respectively. On April 3, 2017, the Company acquired the iRobot-related distribution business of SODC, and on October 2, 2017, the Company acquired Robopolis (see Note 3). The Company maintains its cash in bank deposit accounts at high quality financial institutions. The individual balances, at times, may exceed federally insured limits. Net Income Per Share Basic income per share is calculated using the Company's weighted-average outstanding common shares. Diluted income per share is calculated using the Company's weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. The following table presents the calculation of both basic and diluted net income per share: Fiscal Year Ended December 30, December 31, January 2, Net income $ 50,964 $ 41,939 $ 44,130 Weighted-average shares outstanding 27,611 27,698 29,550 Dilutive effect of employee stock options and restricted shares 1,142 594 557 Diluted weighted-average shares outstanding 28,753 28,292 30,107 Basic income per share $ 1.85 $ 1.51 $ 1.49 Diluted income per share $ 1.77 $ 1.48 $ 1.47 Restricted stock units and stock options representing approximately 0.0 million , 0.4 million and 0.5 million shares of common stock for the fiscal years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , respectively, were excluded from the computation of diluted earnings per share as their effect would have been antidilutive. Recently Adopted Accounting Standards In May 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards update (ASU) No. 2017-09, "Stock Compensation – Scope of Modification Accounting," that clarifies that all changes to share-based payment awards are not necessarily accounted for as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award changes as a result of the change in terms or conditions. This guidance is effective prospectively beginning January 1, 2018, with early adoption permitted. This guidance will apply to any future modifications. During the fourth quarter of 2017, the Company adopted this standard, which did not have an impact on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-01, "Business Combinations; Clarifying the Definition of a Business." ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. This guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. During the fourth quarter of 2017, the Company adopted this standard, which did not have an impact on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other." ASU 2017-04 eliminates step 2 from the goodwill impairment test, instead requiring that an entity recognize an impairment charge for the amount by which the carrying amount of goodwill exceeds the reporting unit's fair value. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. During the fourth quarter of 2017, the Company adopted this standard, which did not have a material impact on the Company's consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments." ASU 2016-15 refines how companies classify certain aspects of the cash flow statement in regards to debt prepayment, settlement of debt instruments, contingent consideration payments, proceeds from insurance claims and life insurance policies, distribution from equity method investees, beneficial interests in securitization transactions and separately identifiable cash flows. ASU 2016-15 is effective for annual periods beginning after December 15, 2017, and for interim periods within fiscal years beginning after December 15, 2018. Early adoption is permitted. During the fourth quarter of 2017, the Company adopted this standard, which did not have a material impact on the Company's consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, "Improvements to Employee Share-Based Payment Accounting," which simplifies several aspects of the accounting for share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. Under the new standard, all excess tax benefits and tax deficiencies are recorded as a component of the provision for income taxes in the reporting period in which they occur. Additionally, ASU 2016-09 requires that the Company present excess tax benefits on the Statement of Cash Flows as an operating activity. The Company adopted ASU 2016-09 effective January 1, 2017 and elected to apply this adoption prospectively. Upon the adoption, the Company elected to account for forfeitures of share-based payments as they occur prospectively. Prior periods have not been adjusted. As of the adoption date, this standard did not have a material impact on the Company's consolidated financial statements. In July 2015, the FASB issued ASU No. 2015-11, "Inventory: Simplifying the Measurement of Inventory." ASU 2015-11 applies only to inventory for which

Business Combinations (Notes)

Business Combinations (Notes)	12 Months Ended
	Dec. 30, 2017
Business Combinations [Abstract]
Business Combinations	3. Business Combinations Acquisition of Robopolis On October 2, 2017, the Company closed the acquisition of its largest European distributor, Robopolis SAS, a French company (Robopolis), subsequently renamed to iRobot France SAS. The initial purchase price was approximately $170.1 million in cash, net of acquired cash of $38.0 million , subject to the finalization of the working capital adjustment in accordance with the stock purchase agreement. The acquisition will better enable the Company to maintain its leadership position and grow its business in several Western European countries through direct control of pre- and post-sales market activities including sales, marketing, branding, channel relationships and customer service. The results of operations for this acquisition have been included in the Company’s operating results since the acquisition date. The estimated fair values of assets acquired and liabilities assumed are provisional and are based on the information that was available as of the acquisition date to estimate the fair value of assets acquired and liabilities assumed. Therefore, the provisional measurements of fair value reflected are subject to change and such changes could be significant. The Company is continuing to analyze certain pre-acquisition income tax filing positions of Robopolis in various taxing jurisdictions that will assist the Company in finalizing the amounts to record any assumed uncertain income tax positions. The Company expects to finalize the valuation and complete the purchase price allocation as soon as practicable, but no later than one year from the acquisition date. The following table summarizes the preliminary allocation of the purchase price (in thousands): Cash $ 37,981 Accounts receivable 21,426 Inventory 36,304 Goodwill 79,558 Intangible assets 36,597 Other assets 2,456 Total assets 214,322 Accounts payable (29,391 ) Accrued expenses (3,376 ) Deferred tax liabilities (10,833 ) Other liabilities (645 ) Total liabilities assumed (44,245 ) Net assets acquired $ 170,077 The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives: Useful Life Fair Value (in thousands) Reacquired distribution rights 2.25 years $ 29,296 Customer relationships 14 years 7,029 Non-competition agreements 3 years 272 Total $ 36,597 The amount assigned to identifiable intangible assets acquired was based on their fair values determined as of the acquisition date, primarily using the income approach by discounting to present value the free cash flows expected to be generated by each asset over its remaining life. The discount rate used was approximately 14.5% . Reacquired distribution rights are amortized on an accelerated basis while all other intangible assets are amortized over their respective estimated useful lives on a straight-line basis, consistent with the pattern in which the economic benefits are being utilized. Goodwill represents the excess of the purchase price over the fair values of the net tangible and intangible assets acquired. In accordance with current accounting standards, the goodwill is not being amortized and will be tested for impairment at least annually. None of the goodwill associated with this transaction will be deductible for tax purposes. Acquisition of Sales On Demand Corporation On April 3, 2017, the Company closed its acquisition of the iRobot-related distribution business of Sales On Demand Corporation (SODC), iRobot Japan G.K., for approximately $16.6 million in cash, equal to the book value of the acquired assets. The acquisition will better enable the Company to maintain its leadership position and accelerate the growth of its business in Japan through direct control of pre- and post-sales market activities including sales, marketing, branding, channel relationships and customer service. It also expands the Company's presence and customer outreach opportunities in Japan. The acquisition was a stock purchase. The results of operations for this acquisition have been included in the Company's operating results since the acquisition date. During the three months ended September 30, 2017, the Company finalized the purchase price allocation and made measurement period adjustments to the provisional amounts reported as the estimated fair values of assets acquired. These measurement period adjustments resulted in a $2.2 million non-taxable gain on business acquisition which represents the excess of the fair value of the net assets acquired over the purchase price. The gain on business acquisition was recorded within other income, net in the consolidated statements of income. The Company believes that the gain on business acquisition was due to the transaction not being subjected to a competitive bidding process and the purchase price being determined based on the net book value of the net assets acquired. The following table summarizes the final allocation of the purchase price (in thousands): Cash $ 125 Accounts receivable, net (1) (5,496 ) Inventory 18,290 Other assets 2,065 Deferred tax assets, net 409 Goodwill — Intangible assets 8,640 Total assets acquired 24,033 Accrued expenses and other current liabilities (4,450 ) Other liabilities (691 ) Total liabilities assumed (5,141 ) Net assets acquired $ 18,892 Gain on business acquisition (2,243 ) Total purchase price $ 16,649 (1) The accounts receivable balance reflects reserves for product returns, discounts and promotions assumed as part of the acquisition. The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives: Useful Life Fair Value (in thousands) Customer relationships 13 years $ 4,490 Reacquired distribution rights 9 months 4,150 Total $ 8,640 Pro Forma Results (Unaudited) The following table shows unaudited pro forma results of operations as if we had acquired Robopolis on January 3, 2016 (dollars in thousands, except per share amounts): Fiscal Year Ended December 30, December 31, Revenue $ 901,612 $ 718,917 Net income $ 51,887 $ 53,320 Net income per share: Basic income per share $ 1.88 $ 1.93 Diluted income per share $ 1.80 $ 1.88 We have not furnished pro forma financial information relating to our other fiscal 2017 acquisition because such information is not material, individually or in the aggregate, to our financial results. The unaudited pro forma results of operations are not necessarily indicative of the actual results that would have occurred had the transactions taken place at the beginning of the periods indicated.

Divestiture (Notes)

Divestiture (Notes)	12 Months Ended
	Dec. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Divestiture	4. Divestiture In April 2016, the Company completed the sale of its defense and security business unit to iRobot Defense Holdings, Inc., a portfolio company of Arlington Capital Partners. The final purchase price, including adjustments for working capital and indebtedness, was $24.5 million . The Company recognized a gain of $0.4 million on the sale of assets. The sale of its defense and security business did not meet the criteria for discontinued operations presentation as it did not represent a strategic shift that had a major effect on the Company's operations and financial results.

Inventory

Inventory	12 Months Ended
	Dec. 30, 2017
Inventory Disclosure [Abstract]
Inventory	5. Inventory Inventory consists of the following at: December 30, December 31, (In thousands) Raw materials $ 4,036 $ 4,717 Finished goods 102,896 45,861 $ 106,932 $ 50,578

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 30, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	6. Property and Equipment Property and equipment consists of the following at: December 30, December 31, (In thousands) Computer and equipment $ 10,669 $ 7,378 Furniture 4,120 2,906 Machinery 14,202 9,154 Tooling 31,783 20,487 Leasehold improvements 26,136 21,383 Business applications software 12,757 9,471 99,667 70,779 Less: accumulated depreciation 55,088 43,247 $ 44,579 $ 27,532 Depreciation expense for the years ended December 30, 2017 , December 31, 2016 and January 2, 2016 was $12.3 million , $10.0 million , and $11.4 million , respectively.

Goodwill and other intangible a

Goodwill and other intangible assets	12 Months Ended
	Dec. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and other intangible assets	7. Goodwill and other intangible assets The following table summarizes the activity in the carrying amount of goodwill for fiscal years 2017 and 2016: (In thousands) Balance as of January 2, 2016 $ 48,751 Divestiture (1) (7,710 ) Balance as of December 31, 2016 41,041 Acquisitions (Note 3) 79,558 Effect of foreign currency translation 841 Balance as of December 30, 2017 $ 121,440 (1) In April 2016, the Company completed the sale of its defense and security business unit and therefore the goodwill balance assigned to the defense and security business unit was written off during the three months ended July 2, 2016. Intangible assets at December 30, 2017 and December 31, 2016 consisted of the following: December 30, 2017 December 31, 2016 Cost Accumulated Amortization Net Cost Accumulated Amortization Net (In thousands) Completed technology $ 26,900 $ 18,150 $ 8,750 $ 26,900 $ 14,693 $ 12,207 Tradename 100 100 — 100 100 — Customer relationships 11,594 418 11,176 — — — Reacquired distribution rights 33,760 9,226 24,534 — — — Non-competition agreements 275 23 252 — — — Total $ 72,629 $ 27,917 $ 44,712 $ 27,000 $ 14,793 $ 12,207 Amortization expense related to acquired intangible assets was $13.1 million , $3.5 million , and $3.5 million for the fiscal years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , respectively. The estimated future amortization expense related to current intangible assets in each of the five succeeding fiscal years is expected to be as follows: (In thousands) 2018 $ 19,767 2019 13,188 2020 1,950 2021 1,714 2022 1,489 Thereafter 6,604 Total $ 44,712

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 30, 2017
Accrued Liabilities, Current [Abstract]
Accrued Expenses	8. Accrued Expenses Accrued expenses consist of the following at: December 30, December 31, (In thousands) Accrued bonus 20,443 14,226 Accrued warranty 11,264 8,464 Accrued other compensation 9,071 6,789 Accrued sales and other taxes 7,256 422 Accrued federal and state income taxes 7,110 1,059 Accrued sales and marketing 3,299 404 Accrued direct fulfillment costs 1,885 1,722 Accrued customer deposits 1,324 1,171 Accrued accounting fees 1,221 686 Accrued rent — 327 Accrued other 10,774 5,599 $ 73,647 $ 40,869

Working Capital Facilities

Working Capital Facilities	12 Months Ended
	Dec. 30, 2017
Debt Disclosure [Abstract]
Revolving Line of Credit	9. Working Capital Facilities Credit Facility The Company has an unsecured revolving credit facility with Bank of America, N.A., which is available to fund working capital and other corporate purposes. As of December 30, 2017 , the total amount of the credit facility was $75.0 million and the full amount was available for borrowing. The interest on loans under the credit facility will accrue, at the Company's election, at either (1) LIBOR plus a margin, currently equal to 1.0% , based on the Company's ratio of indebtedness to Adjusted EBITDA (the "Eurodollar Rate"), or (2) the lender's base rate. The lender's base rate is equal to the highest of (1) the federal funds rate plus 0.5% , (2) the lender's prime rate and (3) the Eurodollar Rate plus 1.0% . The credit facility will terminate and all amounts outstanding thereunder will be due and payable in full on December 20, 2018 . As of December 30, 2017 , the Company had no outstanding borrowings under its revolving credit facility. This credit facility contains customary terms and conditions for credit facilities of this type, including restrictions on the Company's ability to incur or guarantee additional indebtedness, create liens, enter into transactions with affiliates, make loans or investments, sell assets, pay dividends or make distributions on, or repurchase, the Company's stock, and consolidate or merge with other entities. In addition, the Company is required to meet certain financial covenants customary with this type of agreement, including maintaining a maximum ratio of indebtedness to Adjusted EBITDA and a minimum specified interest coverage ratio. This credit facility contains customary events of default, including for payment defaults, breaches of representations, breaches of affirmative or negative covenants, cross defaults to other material indebtedness, bankruptcy and failure to discharge certain judgments. If a default occurs and is not cured within any applicable cure period or is not waived, the Company's obligations under the credit facility may be accelerated. As of December 30, 2017 , the Company was in compliance with all covenants under its credit facility. Letter of Credit Facility The Company has an unsecured revolving letter of credit facility with Bank of America, N.A. The credit facility is available to fund letters of credit on the Company's behalf up to an aggregate outstanding amount of $5 million . The Company may terminate at any time, subject to proper notice, or from time to time permanently reduce the amount of the credit facility. The Company pays a fee on outstanding letters of credit issued under the credit facility of up to 1.5% per annum of the outstanding letters of credit. The maturity date for letters of credit issued under the credit facility must be no later than 365 days following the maturity date of the credit facility. As of December 30, 2017 , there were letters of credit outstanding of $1.0 million under the revolving letter of credit facility. The credit facility contains customary terms and conditions for credit facilities of this type, including restrictions on the Company's ability to incur or guarantee additional indebtedness, create liens, enter into transactions with affiliates, make loans or investments, sell assets, pay dividends or make distributions on, or repurchase stock, and consolidate or merge with other entities. In addition, the Company is required to meet certain financial covenants customary with this type of agreement, including maintaining a maximum ratio of indebtedness to Adjusted EBITDA and a minimum specified interest coverage ratio. The credit facility also contains customary events of default, including for payment defaults, breaches of representations, breaches of affirmative or negative covenants, cross defaults to other material indebtedness, bankruptcy, and failure to discharge certain judgments. If a default occurs and is not cured within any applicable cure period or is not waived, the lender may accelerate the obligations under the credit facility. As of December 30, 2017 , the Company was in compliance with all covenants under the revolving letter of credit facility.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities (Notes)	12 Months Ended
	Dec. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	10. Derivative Instruments and Hedging Activities The Company operates internationally and, in the normal course of business, is exposed to fluctuations in foreign currency exchange rates. The foreign currency exposures typically arise from transactions denominated in currencies other than the functional currency of the Company's operations, primarily the Japanese Yen, Canadian dollar and the Euro. The Company uses derivative instruments that are designated in cash flow hedge relationships to reduce or eliminate the effects of foreign exchange rate changes on purchases and sales. These contracts typically have maturities of fourteen months or less. At December 30, 2017 and December 31, 2016 , the Company had outstanding cash flow hedges with a total notional value of $73.7 million and $0.0 million , respectively. The Company also enters into economic hedges that are not designated as hedges from an accounting standpoint to reduce or eliminate the effects of foreign exchange rate changes typically related to short term trade receivables and payables. These contracts typically have maturities of two months or less. At December 30, 2017 and December 31, 2016 , the Company had outstanding economic hedges with a total notional value of $36.6 million and $8.1 million , respectively. The fair values of derivative instruments are as follows: Fair Value Classification December 30, 2017 December 31, 2016 (In thousands) Derivatives not designated as hedging instruments: Foreign currency option contracts Other current assets $ — $ 180 Foreign currency forward contracts Other current assets 413 — Foreign currency forward contracts Accrued expenses 221 43 Derivatives designated as cash flow hedges: Foreign currency forward contracts Other current assets $ 488 $ — Foreign currency forward contracts Other assets 116 — Foreign currency forward contracts Accrued expenses 279 — Gains (losses) associated with derivative instruments not designated as hedging instruments are as follows: Fiscal year ended Classification December 30, 2017 December 31, 2016 (In thousands) Gain (loss) recognized in income Other income, net $ (444 ) $ 29 The following tables reflect the effect of foreign exchange forward contracts that are designated as cash flow hedging instruments for the years ended December 30, 2017 and December 31, 2016 (in thousands): Effective Portion Ineffective Portion Gain (loss) recognized in OCI on Derivative (1) Gain (loss) reclassified from accumulated OCI into income (2) Gain (loss) recognized in income (3) Fiscal year ended Fiscal year ended Fiscal year ended December 30, 2017 December 31, 2016 Classification December 30, 2017 December 31, 2016 Classification December 30, 2017 December 31, 2016 Foreign currency forward contracts $ 584 $ — Revenue $ 320 $ — Other income, net $ (5 ) $ — Cost of revenue $ (63 ) $ — (1) The amount represents the change in fair value of derivative contracts due to changes in spot rates. (2) The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings. (3) The amount represents the change in fair value of derivative contracts due to changes in the forward rates. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	11. Fair Value Measurements The Company’s financial assets and liabilities measured at fair value on a recurring basis at December 30, 2017 , were as follows: Fair Value Measurements as of December 30, 2017 Description Level 1 Level 2 (1) Level 3 (In thousands) Assets: Money market funds $ 3,165 $ — $ — Corporate and government bonds — 37,225 — Derivative instruments (Note 10) — 1,017 — Total assets measured at fair value $ 3,165 $ 38,242 $ — Liabilities: Derivative instruments (Note 10) $ — $ 500 $ — Total liabilities measured at fair value $ — $ 500 $ — The Company’s financial assets and liabilities measured at fair value on a recurring basis at December 31, 2016 , were as follows: Fair Value Measurements as of December 31, 2016 Description Level 1 Level 2 (1) Level 3 (In thousands) Assets: Money market funds $ 156,980 $ — $ — Corporate and government bonds — 39,930 — Derivative instruments (Note 10) — 180 — Total assets measured at fair value $ 156,980 $ 40,110 $ — Liabilities: Derivative instruments (Note 10) $ — $ 43 $ — Total liabilities measured at fair value $ — $ 43 $ — (1) Level 2 fair value estimates are based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 30, 2017
Equity [Abstract]
Stockholders' Equity	12. Stockholders' Equity Preferred Stock The Company has authorized 5,000,000 shares of undesignated preferred stock with a par value of $0.01 per share. None of the preferred shares were issued and outstanding at December 30, 2017 and December 31, 2016. Common Stock Common stockholders are entitled to one vote for each share held and to receive dividends if and when declared by the Board of Directors and subject to and qualified by the rights of holders of the preferred stock. Upon dissolution or liquidation of the Company, holders of common stock will be entitled to receive all available assets subject to any preferential rights of any then outstanding preferred stock. Share Repurchase Activity On April 2, 2014, the Company announced a stock repurchase program. Under the program, the Company could purchase up to $50 million of its common stock from May 1, 2014 to April 30, 2015 . On March 19, 2015, the Company announced an additional stock repurchase program, which authorized the repurchase of $50 million of its common stock from May 1, 2015 to April 30, 2016 . On December 28, 2015, the Company replaced the then-current stock repurchase program with a new stock repurchase program, effective January 4, 2016 and ending on December 31, 2016, pursuant to which the Company was authorized to purchase up to one million shares or $40 million of its common stock. On March 1, 2016, the Company replaced the then-current stock repurchase program and entered into an accelerated share repurchase (ASR) agreement to repurchase an aggregate of $85.0 million of common stock. The Company did not repurchase any shares of common stock during fiscal year 2017. During fiscal year 2016 and 2015, the Company repurchased 2,641,122 shares totaling $97.0 million and 1,260,276 shares totaling $37.4 million , respectively, in the open market under these stock repurchase plans.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	13. Stock-Based Compensation The Company has options outstanding under three stock incentive plans: the 2005 Stock Option and Incentive Plan (the "2005 Plan"), the Evolution Robotics, Inc. 2007 Stock Plan (the "2007 Plan") and the 2015 Stock Option and Incentive Plan (the "2015 Plan" and together with the 2005 Plan and the 2007 Plan, the "Plans"). All options that remained outstanding under the 2004 Stock Option and Incentive Plan as of December 27, 2014 were exercised during fiscal 2015. The 2015 Plan is the only one of the three plans under which new awards may currently be granted. Under the 2015 Plan, which became effective May 20, 2015, 3,100,000 shares were initially reserved for issuance in the form of incentive stock options, non-qualified stock options, stock appreciation rights, deferred stock awards, restricted stock units, unrestricted stock awards, cash-based awards, performance share awards and dividend equivalent rights. Stock awards 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 2015 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. The grant of any full value award (e.g., restricted stock units) under the 2015 Plan is counted against the share reserve for future grants under the 2015 Plan as 1.61 shares for every one share actually subject to such award. As of December 30, 2017 , there were 590,655 shares available for future grant under the 2015 Plan. The Company recognized $19.8 million , $16.0 million and $14.2 million of stock-based compensation expense during the fiscal years ended December 30, 2017 , December 31, 2016, and January 2, 2016, respectively. Stock Options Options granted under the Plans are exercisable in full at any time subsequent to vesting, generally vest over four years, and expire five or ten years from the date of grant or, if earlier, 90 days from employee termination. The exercise price of stock options is typically equal to the closing price on The Nasdaq Global Select Market on the date of grant. As of December 30, 2017 , the unamortized compensation costs associated with stock options was $4.0 million with a weighted-average remaining recognition period of 2.07 years. The following table summarizes stock option activity for fiscal years 2017, 2016 and 2015: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value(1) Outstanding at December 27, 2014 1,473,320 $ 22.89 Granted 323,104 32.58 Exercised (390,085 ) 16.57 Canceled (118,789 ) 28.41 Outstanding at January 2, 2016 1,287,550 $ 26.73 Granted 314,770 38.03 Exercised (456,498 ) 20.47 Canceled (57,648 ) 33.28 Outstanding at December 31, 2016 1,088,174 $ 32.27 Granted 10,975 57.33 Exercised (367,267 ) 28.79 Canceled (18,928 ) 36.72 Outstanding at December 30, 2017 712,954 $ 34.34 4.27 years $30.2 million Vested and expected to vest at December 30, 2017 712,954 $ 34.34 4.27 years $30.2 million Exercisable as of December 30, 2017 399,163 $ 32.10 3.62 years $17.8 million _________________________ (1) The aggregate intrinsic value on the table above represents the difference between the Company's closing stock price on December 30, 2017 of $76.70 and the exercise price of the underlying in-the-money option. The fair value of each option grant for the fiscal years ended December 30, 2017 , December 31, 2016 , and January 2, 2016 was computed on the grant date using the Black-Scholes option-pricing model with the following assumptions: Fiscal Year Ended December 30, December 31, January 2, Risk-free interest rate 2.11% 1.17% — 1.89% 1.47% — 1.75% Expected dividend yield — — — Expected life 4.01 years 4.01 — 4.03 years 3.98 — 4.02 years Expected volatility 38.0% 38.9% — 42.1% 46.5% — 52.4% The risk-free interest rate is derived from the average U.S. Treasury constant maturity rate, which approximates the rate in effect at the time of grant, commensurate with the expected life of the instrument. The dividend yield is zero based upon the fact the Company has never paid and has no present intention to pay cash dividends. The Company utilizes company specific historical data for purposes of establishing expected volatility and expected term. During fiscal years 2017, 2016, and 2015, the total intrinsic value of stock options exercised was $21.8 million , $10.3 million , and $5.9 million , respectively. The following table summarizes information about stock options outstanding at December 30, 2017 : Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Remaining Contractual Life Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 3.54 - $ 26.59 113,447 1.90 years $ 23.00 113,447 $ 23.00 29.60 - 32.38 109,187 4.54 31.13 55,396 31.33 33.14 - 33.14 108,113 5.19 33.14 39,085 33.14 33.29 - 34.30 116,942 4.06 34.01 66,770 33.99 35.43 - 37.08 58,858 3.52 35.72 49,232 35.60 37.62 - 37.62 99,370 5.44 37.62 31,467 37.62 39.09 - 39.09 37,589 5.69 39.09 9,434 39.09 43.35 - 43.35 29,605 3.18 43.35 27,178 43.35 57.33 - 57.33 10,975 6.19 57.33 — — 58.55 - 58.55 28,868 5.94 58.55 7,154 58.55 $ 3.54 - $58.55 712,954 4.27 years $ 34.34 399,163 $ 32.10 Restricted Stock Units Restricted stock units entitle the holder to a specific number of shares of common stock upon vesting, typically over a four -year period. As of December 30, 2017 , the unamortized compensation costs associated with restricted stock units was $39.3 million with a weighted-average remaining recognition period of 2.52 years. The following table summarizes the restricted stock unit activity for fiscal years 2017, 2016 and 2015: Number of Shares Underlying Restricted Stock Weighted Average Grant Date Fair Value Outstanding at December 27, 2014 880,138 $ 30.10 Granted 505,277 36.88 Vested (340,754 ) 29.13 Forfeited (110,784 ) 30.82 Outstanding at January 2, 2016 933,877 $ 31.42 Granted 458,237 37.93 Vested (358,018 ) 30.81 Forfeited (98,917 ) 32.13 Outstanding at December 31, 2016 935,179 $ 35.07 Granted 396,164 72.63 Vested (351,543 ) 33.73 Forfeited (41,347 ) 39.52 Outstanding at December 30, 2017 938,453 $ 51.24 The aggregate intrinsic value of outstanding restricted stock units at December 30, 2017 was $72.0 million based on the Company's closing stock price on December 30, 2017 of $76.70 , with a weighted average remaining contractual term of 1.50 years. Performance Based Restricted Stock Units The Company grants performance-based restricted stock units (PSUs) to certain of its employees. The PSUs have performance metrics based on financial performance of the Company measured at the end of a three -year performance period. The performance metric for these awards is operating income percent, with a threshold requirement for a minimum amount of revenue growth. The number of shares actually earned at the end of the three year period will range from 0% to 200% of the target number of PSUs granted based on the Company’s performance against the performance conditions. The unamortized fair value as of December 30, 2017 associated with performance based restricted stock units was $5.6 million with a weighted-average remaining recognition period of 1.39 years. The following table summarizes the performance based restricted stock unit activity for fiscal years 2017, 2016 and 2015: Number of Weighted Average Outstanding at December 27, 2014 29,717 $ 43.35 Granted 71,133 34.30 Vested — — Forfeited (10,358 ) 38.60 Outstanding at January 2, 2016 90,492 $ 36.78 Granted 82,085 33.36 Vested (5,625 ) 34.30 Forfeited (3,041 ) 34.30 Outstanding at December 31, 2016 163,911 $ 35.03 Granted 105,650 57.33 Vested (24,792 ) 43.35 Forfeited (2,708 ) 39.71 Outstanding at December 30, 2017 242,061 $ 43.97 _________________________ (1) Includes the target number of PSUs. The aggregate intrinsic value of outstanding PSUs was $18.6 million based on the Company's closing stock price on December 30, 2017 of $76.70 with a weighted average remaining contractual term of 1.39 years. Employee Stock Purchase Plan In May 2017, the Company’s stockholders approved the 2017 Employee Stock Purchase Plan (ESPP). The Company reserved a total of 700,000 shares of common stock for issuance under this plan. The ESPP is administered over six -month offering periods beginning November 15 and May 15 of each year. Eligible employees can contribute 1% to 15% of their compensation each period up to $4,000 , for the purchase of common stock not to exceed 1,000 shares per the six-month period. On the last business day of each period, shares of common stock are purchased at a purchase price of 85% of the lower of the fair market values of the stock as of the beginning and the end of the offering period. The first offering period began November 15, 2017, resulting in an immaterial stock-based compensation expense for the year ended December 30, 2017.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies Legal Proceedings From time to time and in the ordinary course of business, the Company is subject to various claims, charges and litigation. The outcome of litigation cannot be predicted with certainty and some lawsuits, claims or proceedings may be disposed of unfavorably to us, which could materially affect our financial condition or results of operations. Lease Obligations The Company leases its facilities. Rental expense under operating leases for fiscal years 2017 , 2016 and 2015 amounted to $8.9 million , $6.0 million , and $4.9 million , respectively. Future minimum rental payments under operating leases were as follows as of December 30, 2017 : Operating Leases 2018 $ 6,361 2019 6,901 2020 6,506 2021 6,502 2022 6,498 Thereafter 39,839 Total minimum lease payments $ 72,607 Outstanding Purchase Orders At December 30, 2017 , we had outstanding purchase orders aggregating approximately $74.4 million . The purchase orders, the majority of which are with our contract manufacturers for the purchase of inventory in the normal course of business, are for manufacturing and non-manufacturing related goods and services, and are generally cancelable without penalty. In circumstances where we determine that we have financial exposure associated with any of these commitments, we record a liability in the period in which that exposure is identified. 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. The term of these indemnification agreements is generally perpetual any time 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 December 30, 2017 and December 31, 2016 , respectively. Government Contract Contingencies Prior to the completion of the divestiture of our defense and security business unit during the second quarter of 2016, the Company had several prime contracts with the U.S. federal government which did not contain a limitation of liability provision, creating a risk of responsibility for direct and consequential damages. Several subcontracts with prime contractors hold the prime contractor harmless against liability that stems from our work and do not contain a limitation of liability. These provisions could cause substantial liability for the Company. In addition, the Company is subject to audits by the U.S. federal government as part of routine audits of government contracts. As part of an audit, these agencies may review the Company’s performance on contracts, cost structures and compliance with applicable laws, regulations and standards. If any of its costs are found to be allocated improperly to a specific contract, the costs may not be reimbursed and any costs already reimbursed for such contract may have to be refunded. Accordingly, an audit could result in a material adjustment to our revenue and results of operations. Annually, the Company submitted final indirect billing rates to DCMA based upon actual costs incurred throughout the year. These final billing rates are subject to audit by DCAA. As of December 30, 2017 , fiscal year 2016 is open for audit by DCAA. Warranty The Company provides warranties on most products and has established a reserve for warranty based on estimated warranty costs. The reserve is included as part of accrued expenses (Note 8) in the accompanying consolidated balance sheets. Activity related to the warranty accrual was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Balance at beginning of period $ 8,464 $ 6,907 $ 7,769 Liability assumed (1) 2,186 — — Provision 8,591 7,494 4,598 Warranty usage (2) (7,977 ) (5,937 ) (5,460 ) Balance at end of period $ 11,264 $ 8,464 $ 6,907 __________________________________ (1) Warranty assumed as part of the acquisition of the iRobot-related distribution business of Sales On Demand Corporation (see Note 3). (2) Warranty usage includes costs incurred for warranty obligations and, for the twelve month period ended December 31, 2016, the release of warranty liabilities associated with the divestiture of the defense and security business unit.

Employee Benefits (Notes)

Employee Benefits (Notes)	12 Months Ended
	Dec. 30, 2017
Retirement Benefits [Abstract]
Employee Benefits	15. Employee Benefits The Company sponsors a retirement plan under Section 401(k) of the Internal Revenue Code (the "Retirement Plan"). All Company employees, with the exception of temporary, contract and international employees are eligible to participate in the Retirement Plan after satisfying age and length of service requirements prescribed by the plan. Under the Retirement Plan, employees may make tax-deferred contributions, and the Company, at its sole discretion, and subject to the limits prescribed by the IRS, may make either a nonelective contribution on behalf of all eligible employees or a matching contribution on behalf of all plan participants. The Company elected to make a matching contribution of approximately $2.4 million , $1.7 million and $1.8 million for the plan years ended December 30, 2017 , December 31, 2016 and January 2, 2016 ("Plan-Year 2017," "Plan-Year 2016" and "Plan-Year 2015"), respectively. The employer contribution represents a matching contribution at a rate of 50% of each employee’s first six percent contribution. Accordingly, each employee participating during Plan-Year 2017, Plan-Year 2016 and Plan-Year 2015 is entitled up to a maximum of three percent of his or her eligible annual payroll.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes Income (loss) before provision for income taxes was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Domestic $ 71,382 $ 61,706 $ 62,391 Foreign 4,984 (345 ) 580 Income before income taxes $ 76,366 $ 61,361 $ 62,971 The components of income tax expense were as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Current Federal $ 17,555 $ 17,639 $ 20,033 State 1,691 1,054 972 Foreign 7,355 310 121 Total current income tax provision 26,601 19,003 21,126 Deferred Federal $ 6,664 $ 781 $ (1,657 ) State (2,470 ) (95 ) (628 ) Foreign (5,393 ) (267 ) — Total deferred income tax provision (1,199 ) 419 (2,285 ) Total income tax provision $ 25,402 $ 19,422 $ 18,841 Due to the adoption of ASU 2016-09 in 2017, all excess tax benefits and deficiencies are recognized as income tax expense in the Company’s consolidated statement of income. This will result in increased volatility in the Company’s effective tax rate. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "Act") was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21% for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system and a one-time transition tax on the mandatory deemed repatriation of foreign earnings. The Company has estimated the provision for income taxes in accordance with the Act and guidance available as of the date of this filing and as a result have recorded a one-time income tax provision of $11.9 million as additional income tax provision in the fourth quarter of 2017, the period in which the legislation was enacted. The one-time income tax provision includes $8.9 million related to the remeasurement of certain deferred tax assets and liabilities based on the tax rates at which they are expected to reverse in the future. The one-time income tax expense also includes a provisional amount of $3.0 million related to the one-time transition tax on the mandatory deemed repatriation of foreign earnings. On December 22, 2017, Staff Accounting Bulletin No. 118 (SAB 118) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. In accordance with SAB 118, the Company has determined that the $3.0 million of current income tax provision recorded relating to the transition tax on the mandatory deemed repatriation of foreign earnings was a provisional amount and a reasonable estimate at December 30, 2017. Additional information and analysis is necessary to complete the calculation and accounting relating to the transition tax on the mandatory deemed repatriation of foreign earnings. Any subsequent adjustments to this amount will be recorded to current income tax provision during the measurement period which is not expected to extend beyond one year from the enactment date. A reconciliation of the expected tax (benefit) expense computed by applying the federal statutory rate to income before income taxes to actual tax expense is as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Expected federal income tax $ 26,728 $ 21,476 $ 22,040 Miscellaneous permanent items 2,979 516 608 State taxes (net of federal benefit) 2,089 1,360 982 Federal and state credits (4,486 ) (2,233 ) (2,767 ) Change in valuation allowance 800 — — Domestic production activities deduction (1,528 ) (1,731 ) (2,145 ) Statute of limitation expirations of uncertain tax positions (106 ) (167 ) (194 ) Excess tax benefits relating to stock-based compensation (11,709 ) — — Tax Cuts and Jobs Act of 2017 11,861 — — Other (1,226 ) 201 317 $ 25,402 $ 19,422 $ 18,841 The components of net deferred tax assets were as follows: December 30, December 31, (In thousands) Deferred tax assets Reserves and accruals $ 24,315 $ 20,737 Tax credits 6,666 5,999 Property and equipment 1,382 1,934 Stock-based compensation 4,277 6,150 Net operating loss carryforwards 144 1,010 Valuation allowance (800 ) — Gross deferred tax assets 35,984 35,830 Deferred tax liabilities Intangible assets 13,419 4,530 Other 573 715 Gross deferred tax liabilities 13,992 5,245 Net deferred tax assets $ 21,992 $ 30,585 The Act includes a mandatory one-time tax on accumulated earnings of foreign subsidiaries, and as a result, all previously unremitted earnings for which no U.S. deferred tax liability had been accrued have now been subject to U.S. tax. Notwithstanding the U.S. taxation of these amounts, the Company intends to continue to invest all of these earnings, as well as the capital in these subsidiaries, indefinitely outside of the U.S. The amount of any unrecognized deferred tax liability on these undistributed earnings would be immaterial. The Company has fully utilized both the federal and state net operating loss carryforwards as of December 30, 2017. The Company had federal and state net operating loss carryforwards of $1.0 million and $8.9 million , respectively, as of December 31, 2016. The Company has fully utilized the federal research and development credit carryforwards as of December 30, 2017 and had $1.0 million of federal research and development credit carryforwards as of December 31, 2016. The Company has state research and development credit carryforwards of $10.1 million and $10.0 million as of December 30, 2017 and December 31, 2016, respectively, which expire from 2026 to 2032. Under the Internal Revenue Code and state law, certain substantial changes in the Company’s ownership could result in an annual limitation on the amount of these tax carryforwards which can be utilized in future years. As of December 30, 2017, the Company has $1.0 million of state research and development credits related to the acquisition of Evolution Robotics that are limited by Section 382 and Section 383, respectively, of the Internal Revenue Code. However, these limitations are not expected to cause any of these state research and development credits to expire prior to being utilized. As of December 30, 2017, the Company recorded a valuation allowance of $0.8 million for certain foreign deferred tax assets for which the Company believes do not meet the "more likely than not" criteria for recognition. A summary of the Company’s adjustments to its gross unrecognized tax benefits in the current year is as follows: Fiscal Year Ended December 30, 2017 December 31, January 2, (in thousands) Balance at beginning of period $ 5,146 $ 6,616 $ 2,491 Increase for tax positions related to the current year 580 2,851 786 Increase (decrease) for tax positions related to prior years (523 ) (4,224 ) 3,533 Decreases for settlements with applicable taxing authorities — — — Decreases for lapses of statute of limitations (613 ) (97 ) (194 ) Balance at end of period $ 4,590 $ 5,146 $ 6,616 The Company accrues interest and, if applicable, penalties for any uncertain tax positions as a component of income tax expense. As of December 30, 2017, December 31, 2016 and January 2, 2016 there were no material accrued interest or penalties. The Company is subject to taxation in the United States (federal and state) and foreign jurisdictions. The statute of limitations for examinations by the Internal Revenue Service (the "IRS") is closed for fiscal years prior to 2014. The statute of limitations for examinations by state tax authorities is closed for fiscal years prior to 2013. Federal and state carryforward attributes that were generated prior to fiscal 2014 and 2013, respectively, may still be adjusted upon examination by the federal 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. The Company is currently under examination by the IRS for the years 2014 and 2015. The Company does not expect a significant change in the amount of unrecognized tax benefits within the next 12 months. If all of the Company's unrecognized tax benefits as of December 30, 2017 were to become recognizable in the future, it would record a $2.0 million benefit, inclusive of interest, to the income tax provision.

Industry Segment, Geographic In

Industry Segment, Geographic Information and Significant Customers	12 Months Ended
	Dec. 30, 2017
Segment Reporting [Abstract]
Industry Segment, Geographic Information and Significant Customers	17. Industry Segment, Geographic Information and Significant Customers Prior to completing the sale of the Company's defense and security business (see Note 4), the Company’s reportable segments consisted of the home business unit and the defense and security business unit. Following this divestiture, which was completed in April 2016, the Company now operates as one operating segment, consumer robots, the results of which are included in the Company's consolidated statements of income and comprehensive income. The Company's consumer robots products are offered 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. Geographic Information For the fiscal years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , sales to non-U.S. customers accounted for 48.8% , 51.2% and 56.0% of total revenue, respectively. Significant Customers For the fiscal years ended December 30, 2017 , December 31, 2016 and January 2, 2016 approximately 62.7% , 72.8% and 76.6% , respectively, of consumer robots revenue resulted from sales to 15 customers. For the fiscal year ended December 30, 2017 , the Company generated 13.5% of total revenue from one of its retailers (Amazon). For the fiscal year ended December 31, 2016 , the Company generated 12.9% , 12.3% and 10.4% of total revenue from its distributor in Japan (Sales On Demand Corporation), a network of affiliated European distributors (Robopolis SAS) and Amazon, respectively. For the fiscal year ended January 2, 2016 , the Company generated 13.3% and 12.7% of total revenue from Sales on Demand Corporation and Robopolis SAS, respectively. On April 3, 2017, the Company acquired the iRobot-related distribution business of Sales On Demand Corporation, and on October 2, 2017, the Company acquired Robopolis SAS (see Note 3).

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 30, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Information (Unaudited)	18. Quarterly Information (Unaudited) The following information has been derived from unaudited consolidated financial statements that, in the opinion of management, include all recurring adjustments necessary for a fair statement of such information (dollars in thousands, except per share amounts): Fiscal Quarter Ended December 30, September 30, July 1, April 1, December 31, October 1, July 2, April 2, (In thousands, except per share amounts) Revenue $ 326,897 $ 205,399 $ 183,148 $ 168,467 $ 212,494 $ 168,610 $ 148,696 $ 130,804 Gross margin 153,542 102,383 89,891 87,343 106,642 81,060 69,652 61,961 Net income 4,620 22,082 7,903 16,359 13,681 19,512 4,814 3,932 Diluted earnings per share $ 0.16 $ 0.76 $ 0.27 $ 0.58 $ 0.49 $ 0.70 $ 0.17 $ 0.13

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation and Foreign Currency Translation The accompanying consolidated financial statements include those of iRobot and its subsidiaries, after elimination of all intercompany balances and transactions. In addition, certain prior year amounts have been reclassified to conform to the current year presentation. iRobot has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP). For the Company's subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated into U.S. dollars at period-end foreign exchange rates. Revenues and expenses are translated into U.S. dollars at the average foreign exchange rates for the period. Translation adjustments are excluded from the determination of net income and are recorded in accumulated other comprehensive income (loss), a separate component of stockholders' equity.
Use of Estimates	Use of Estimates The preparation of these financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenue and expenses and the disclosure of contingent assets and liabilities in the consolidated financial statements. These estimates and judgments, include but are not limited to, revenue recognition (specifically sales returns and other allowances); valuation of goodwill and acquired intangible assets; accounting for business combinations; evaluating loss contingencies; and accounting for income taxes and related valuation allowances. The Company bases these estimates and judgments on historical experience, market participant fair value considerations, projected future cash flows and various other factors that the Company believes are reasonable under the circumstances. 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 primarily derives its revenue from product sales. Until the divestiture of the defense and security business unit in April 2016 (see Note 4), the Company also generated minimal revenue from government 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 and allowances, provided that collection is determined to be reasonably assured and no significant obligations remain. Beginning in the third quarter of 2015, the Company introduced its first connected robot. Each sale of a connected robot represents a multiple-element arrangement containing the robot, an app and potential future unspecified software upgrades. Revenue is allocated to the deliverables based on their relative selling prices which have been determined using best estimate of selling price (BESP), as the Company has not been able to establish vendor specific objective evidence (VSOE) or obtain relevant third party evidence (TPE). Revenue allocated to the app and unspecified software upgrades is then deferred and recognized on a straight-line basis over the period in which the Company expects to provide the upgrades, which is the estimated life of the robot. Sales to retailers of consumer robots are typically subject to agreements allowing for limited rights of return, rebates and price protection. The Company also provides limited rights of returns for direct-to-consumer sales generated through its on-line stores and certain international distributors. Accordingly, the Company reduces revenue for its estimates of liabilities for these rights of return, rebates, and price protection, as well as discounts and promotions, at the time the related sale is recorded. The estimates for rights of return are directly based on specific terms and conditions included in the customer agreements, historical returns experience and various other assumptions that the Company believes are reasonable under the circumstances. In the case of new product introductions, the estimates for returns applied to the new products are based upon the estimates for the most similar predecessor products until such time that the Company has enough actual returns experience for the new products, which is typically two holiday return cycles. At that time, the Company incorporates that data into the development of returns estimates for the new products. The Company updates its analysis of returns on a quarterly basis. If actual returns differ significantly from the Company's estimates, or if modifications to individual customer agreements are entered into that impact their rights of returns, such differences could result in an adjustment to previously established reserves and could have a material impact, either favorably or unfavorably, on the Company’s results of operations for the period in which the actual returns become known or the agreement is modified. In 2016, the Company began selling to one domestic distributor under an agreement that provides product return privileges. As a result, the Company recognizes revenue from sales to this distributor when the product is resold by the distributor. The estimates and adjustments for rebates and price protection are based on specific programs, expected usage and historical experience. Actual results could differ from these estimates. As of December 30, 2017, the Company has reserves for product returns of $42.7 million , discounts and promotions of $58.2 million and price protection of $3.1 million . As of December 31, 2016, the Company had reserves for product returns of $27.7 million , discounts and promotions of $ 22.1 million and price protection of $1.5 million. Prior to the Company's divestiture of the defense and security business unit in April 2016 (see Note 4), the Company generated minimal revenue from government contracts. Under cost-plus-fixed-fee (CPFF) type contracts, the Company recognized revenue based on costs incurred plus a pro rata portion of the total fixed fee. Costs incurred included labor and material that were 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 submitted 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 used, 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 December 30, 2017, fiscal year 2016 is open for audit by DCAA. In the situation where the Company’s anticipated actual billing rates will be lower than the provisional rates used, the Company records a cumulative revenue adjustment in the period in which the rate differential is identified. Revenue on firm fixed price (FFP) contracts was recognized using the percentage-of-completion method. For government product FFP contracts, revenue was recognized as the product was shipped or in accordance with the contract terms. Costs and estimated gross margins on contracts were recorded as revenue as work was performed based on the percentage that incurred costs compared to estimated total costs utilizing the most recent estimates of costs and funding. Revenue earned in excess of billings, if any, was recorded as unbilled revenue. Billings in excess of revenue earned, if any, were recorded as deferred revenue.
Business Combinations	Business Combinations The Company accounts for transactions that represent business combinations under the acquisition method of accounting. The Company allocates the total consideration paid for each acquisition to the assets it acquires and liabilities it assumes based on their fair values as of the date of acquisition, including identifiable intangible assets. The Company bases the fair value of identifiable intangible assets acquired in a business combination on valuations that use information and assumptions determined by management and which consider management’s best estimates of inputs and assumptions that a market participant would use. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to accurately value assets acquired and liabilities assumed at the business combination date, its estimates and assumptions are inherently uncertain and subject to refinement. As a result, during the measurement period, which is generally one year from the acquisition date, any adjustment to the assets acquired and liabilities assumed is recorded against goodwill in the period in which the amount is determined. Any adjustment identified subsequent to the measurement period is included in operating results in the period in which the amount is determined.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original or remaining maturity of three months or less at the time of purchase to be cash equivalents. The Company invests its excess cash primarily in money market funds or savings accounts of major financial institutions. Accordingly, its cash equivalents are subject to minimal credit and market risk. At December 30, 2017 and December 31, 2016 , cash equivalents were comprised of money market funds totaling $3.2 million and $157.0 million , respectively. These cash equivalents are carried at cost, which approximates fair value.
Short Term Investments	Short Term Investments The Company’s investments are classified as available-for-sale and are recorded at fair value with any unrealized gain or loss recorded as an element of stockholders’ equity. The fair value of investments is determined based on quoted market prices at the reporting date for those instruments. As of December 30, 2017 and December 31, 2016 , investments consisted of: December 30, December 31, Cost Fair Cost Fair (In thousands) Corporate and government bonds $ 37,767 $ 37,225 $ 40,439 $ 39,930 Total short term investments $ 37,767 $ 37,225 $ 40,439 $ 39,930 As of December 30, 2017 , the Company’s investments had maturity dates ranging from March 2018 to September 2020. The Company invests primarily in investment grade securities and limits the amount of investment in any single issuer.
Accounts receivable allowances	Accounts receivable allowances Allowance for product returns : The Company records an allowance for product returns for the estimated amount of product that may be returned. The allowance is based on specific terms and conditions included in the customer agreements, historical returns experience and various other assumptions that the Company believes are reasonable under the circumstances. Allowance for discounts and promotions : The Company records an allowance for discounts and promotions related to promotional marketing support, contractual discounts, etc. The allowance is based on specific programs, expected usage and historical experience. Allowance for price protection : The Company records an allowance for price protection for the estimated amount of support expected to be provided to customers for product transitions. The allowance is based on specific programs, expected usage and historical experience. Allowance for doubtful accounts : The Company records an allowance for doubtful accounts for the estimated amount of accounts receivable that may not be collected. The allowance is based on an assessment of customer creditworthiness, historical payment experience and the age of outstanding receivables.
Inventory	Inventory Inventory is stated at the lower of cost or net realizable value with cost being determined using the first-in, first-out (FIFO) method. The Company maintains a reserve for inventory items to provide for an estimated amount of excess or obsolete inventory.
Warranty	Warranty The Company typically provides a one -year warranty (with the exception of European consumer products, which typically have a two -year warranty period) against defects in materials and workmanship and will either repair the goods, provide replacement products at no charge to the customer or refund amounts to the customer for defective products. The Company records estimated warranty costs, based on historical experience by product, at the time revenue is recognized. Actual results could differ from these estimates, which could cause increases or decreases to the warranty reserves in future periods.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and consist primarily of computer equipment, leasehold improvements, business applications software and machinery. Depreciation is computed using the straight-line method over the estimated useful lives as follows: Estimated Useful Life Computer and research equipment 2-5 years Furniture 5 Machinery 2-5 Tooling 2-5 Business applications software 5-7 Capital leases and leasehold improvements Lesser of economic benefit period or term of lease Expenditures for additions, renewals and betterments of property and equipment are capitalized. Expenditures for repairs and maintenance are charged to expense as incurred. As assets are retired or sold, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations.
Goodwill and Other Long-Lived Assets	Goodwill and Other Long-Lived Assets Goodwill represents the excess of the purchase price in a business combination over the fair value of the net tangible and intangible assets acquired. Goodwill is not amortized but rather is assessed 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. Goodwill impairment, if any, is determined by comparing the reporting unit's fair value to its carrying value. An impairment loss is recognized in an amount equal to the excess of the reporting unit's carrying value over its fair value, up to the amount of goodwill allocated to the reporting unit. The Company completes the annual impairment evaluation during the fourth quarter each year. Other long-lived assets consist principally of completed technology, tradename, customer relationships, reacquired distribution rights and non-competition agreements. Reacquired distribution rights are amortized on an accelerated basis while all other intangible assets are amortized over their respective estimated useful lives on a straight-line basis, consistent with the pattern in which the economic benefits are being utilized. The Company periodically evaluates the recoverability of other long-lived assets whenever events and changes in circumstances, such as reductions in demand or significant economic slowdowns in the industry, indicate that the carrying amount of an asset may not be fully recoverable. When indicators of impairment are present, the carrying values of the asset group are evaluated in relation to the future undiscounted cash flows of the underlying business. The net book value of the underlying asset is adjusted to fair value if the sum of the expected discounted cash flows is less than book value. Fair values are based on estimates of market prices and assumptions concerning the amount and timing of estimated future cash flows and assumed discount rates, reflecting varying degrees of perceived risk. The impairment assessment of goodwill and other long-lived assets involves significant estimates and assumptions, which may be unpredictable and inherently uncertain. These estimates and assumptions include identification of reporting units and asset groups, long-term growth rates, profitability, estimated useful lives, comparable market multiples, and discount rates. Any changes in these assumptions could impact the result of the impairment assessment.
Financial Instruments and Hedging Activities	Financial Instruments and Hedging Activities The Company utilizes derivative instruments to hedge specific financial risks including foreign exchange risk. The Company does not engage in speculative hedging activity. In order to account for a derivative instrument as a hedge, specific criteria must be met, including: (i) ensuring at the inception of the hedge that formal documentation exists for both the hedging relationship and the entity’s risk management objective and strategy for undertaking the hedge and (ii) at the inception of the hedge and on an ongoing basis, the hedging relationship is expected to be highly effective in achieving offsetting changes in fair value attributed to the hedged risk during the period that the hedge is designated. Further, an assessment of effectiveness is required whenever financial statements or earnings are reported. Absent meeting these criteria, changes in fair value are recognized in other income, net, in the consolidated statements of income. Once the underlying forecasted transaction is realized, the gain or loss from the derivative designated as a hedge of the transaction is reclassified from accumulated other comprehensive income (loss) to the statement of income, in revenue or cost of revenue. Any ineffective portion of the derivatives designated as cash flow hedges is recognized in current earnings.
Fair Value Measurements	Fair Value Measurements The Company accounts for certain assets and liabilities at fair value. The fair value is established based on a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: • Level 1 - observable inputs such as quoted prices for identical instruments in active markets; • Level 2 - inputs other than quoted prices in active markets that are either directly or indirectly observable; and • Level 3 - unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation through recognition of the fair value of the stock-based compensation as a charge against earnings. The fair value of employee stock options is estimated at the grant date using the Black-Scholes option-pricing model. The fair value for restricted stock awards, time-based restricted stock units and performance-based restricted stock units is based on the closing share price of the Company's common stock on the date of grant. For performance-based restricted stock units, the compensation cost is recognized based on the number of units expected to vest upon the achievement of the performance conditions. The Company recognizes stock-based compensation as expense over the requisite service period. The Company has elected to account for forfeitures as they occur, rather than applying an estimated forfeiture rate, following its adoption of ASU 2016-09 in the first quarter of 2017.
Research and Development	Research and Development Costs incurred in the research and development of the Company’s products are expensed as incurred.
Internal Use Software	Internal Use Software The Company capitalizes costs associated with the development and implementation of software for internal use. At December 30, 2017 and December 31, 2016 , the Company had $12.8 million and $9.5 million , respectively, of costs related to enterprise-wide software included in fixed assets. Capitalized costs are being amortized over the assets’ estimated useful lives. The Company has recorded $1.5 million , $0.4 million and $0.7 million of amortization expense for the years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , respectively.
Advertising Expense	Advertising Expense The Company expenses advertising costs as they are incurred. During the years ended December 30, 2017 , December 31, 2016 and January 2, 2016 advertising expense totaled $91.8 million , $64.4 million and $54.7 million , respectively, and are recorded within the selling and marketing expenses line item.
Income Taxes	Income Taxes Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis using enacted tax rates in effect in the years in which those temporary differences are expected to be recovered or settled in each jurisdiction. A valuation allowance is provided if, based upon the weight of available evidence, it is more likely than not that the related benefits will not be realized. The Company regularly reviews the deferred tax assets for recoverability considering historical profitability, projected future taxable income, future reversals of existing taxable temporary differences, as well as feasible tax planning strategies in each jurisdiction. As of December 30, 2017, the Company recorded a valuation allowance of $0.8 million for certain foreign deferred tax assets for which the Company believes do not meet the "more likely than not" criteria for recognition. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company recognizes interest and penalties, if any, related to unrecognized tax benefits in the income tax provision. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "Act") was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21% for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system and a one-time transition tax on the mandatory deemed repatriation of foreign earnings. We have estimated our provision for income taxes in accordance with the Act and guidance available as of the date of this filing and as a result have recorded a one-time income tax provision of $11.9 million in the fourth quarter of 2017, the period in which the legislation was enacted. The one-time income tax provision includes $8.9 million related to the remeasurement of certain deferred tax assets and liabilities based on the tax rates at which they are expected to reverse in the future. The one-time income tax expense also includes a provisional amount of $3.0 million related to the one-time transition tax on the mandatory deemed repatriation of foreign earnings. On December 22, 2017, Staff Accounting Bulletin No. 118 (SAB 118) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. In accordance with SAB 118, we have determined that the $3.0 million of current income tax provision recorded relating to the transition tax on the mandatory deemed repatriation of foreign earnings was a provisional amount and a reasonable estimate at December 30, 2017. Additional information and analysis is necessary to complete the calculation and accounting relating to the transition tax on the mandatory deemed repatriation of foreign earnings. Any subsequent adjustments to this amount will be recorded to current income tax provision during the measurement period which is not expected to extend beyond one year from the enactment date.
Concentration of Credit Risk and Significant Customers	Concentration of Credit Risk and Significant Customers Financial instruments which potentially expose the Company to concentrations of credit risk consist of accounts receivable. Management believes its credit policies are prudent and reflect normal industry terms and business risk. At December 30, 2017 , one customer accounted for a total of 11.5% of the Company's accounts receivable balance. At December 31, 2016 , three customers accounted for a total of 43.9% of the Company's accounts receivable balance, each of which was greater than 10% of the balance and two of whom secured their balance with guaranteed letters of credit, which together represents 32.5% of the balance. For the fiscal year ended December 30, 2017 , the Company generated 13.5% of total revenue from one of its retailers (Amazon). For the fiscal year ended December 31, 2016 , the Company generated 12.9% , 12.3% and 10.4% of total revenue from its distributor in Japan, Sales On Demand Corporation (SODC), Robopolis SAS, a network of affiliated European distributors (Robopolis) and Amazon, respectively. For the fiscal year ended January 2, 2016 , the Company generated 13.3% and 12.7% of total revenue from SODC and Robopolis, respectively. On April 3, 2017, the Company acquired the iRobot-related distribution business of SODC, and on October 2, 2017, the Company acquired Robopolis (see Note 3). The Company maintains its cash in bank deposit accounts at high quality financial institutions. The individual balances, at times, may exceed federally insured limits.
Net Income Per Share	Net Income Per Share Basic income per share is calculated using the Company's weighted-average outstanding common shares. Diluted income per share is calculated using the Company's weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. The following table presents the calculation of both basic and diluted net income per share: Fiscal Year Ended December 30, December 31, January 2, Net income $ 50,964 $ 41,939 $ 44,130 Weighted-average shares outstanding 27,611 27,698 29,550 Dilutive effect of employee stock options and restricted shares 1,142 594 557 Diluted weighted-average shares outstanding 28,753 28,292 30,107 Basic income per share $ 1.85 $ 1.51 $ 1.49 Diluted income per share $ 1.77 $ 1.48 $ 1.47 Restricted stock units and stock options representing approximately 0.0 million , 0.4 million and 0.5 million shares of common stock for the fiscal years ended December 30, 2017 , December 31, 2016 and January 2, 2016 , respectively, were excluded from the computation of diluted earnings per share as their effect would have been antidilutive
Recent Accounting Pronouncements	Recently Adopted Accounting Standards In May 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards update (ASU) No. 2017-09, "Stock Compensation – Scope of Modification Accounting," that clarifies that all changes to share-based payment awards are not necessarily accounted for as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award changes as a result of the change in terms or conditions. This guidance is effective prospectively beginning January 1, 2018, with early adoption permitted. This guidance will apply to any future modifications. During the fourth quarter of 2017, the Company adopted this standard, which did not have an impact on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-01, "Business Combinations; Clarifying the Definition of a Business." ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. This guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. During the fourth quarter of 2017, the Company adopted this standard, which did not have an impact on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other." ASU 2017-04 eliminates step 2 from the goodwill impairment test, instead requiring that an entity recognize an impairment charge for the amount by which the carrying amount of goodwill exceeds the reporting unit's fair value. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. During the fourth quarter of 2017, the Company adopted this standard, which did not have a material impact on the Company's consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments." ASU 2016-15 refines how companies classify certain aspects of the cash flow statement in regards to debt prepayment, settlement of debt instruments, contingent consideration payments, proceeds from insurance claims and life insurance policies, distribution from equity method investees, beneficial interests in securitization transactions and separately identifiable cash flows. ASU 2016-15 is effective for annual periods beginning after December 15, 2017, and for interim periods within fiscal years beginning after December 15, 2018. Early adoption is permitted. During the fourth quarter of 2017, the Company adopted this standard, which did not have a material impact on the Company's consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, "Improvements to Employee Share-Based Payment Accounting," which simplifies several aspects of the accounting for share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. Under the new standard, all excess tax benefits and tax deficiencies are recorded as a component of the provision for income taxes in the reporting period in which they occur. Additionally, ASU 2016-09 requires that the Company present excess tax benefits on the Statement of Cash Flows as an operating activity. The Company adopted ASU 2016-09 effective January 1, 2017 and elected to apply this adoption prospectively. Upon the adoption, the Company elected to account for forfeitures of share-based payments as they occur prospectively. Prior periods have not been adjusted. As of the adoption date, this standard did not have a material impact on the Company's consolidated financial statements. In July 2015, the FASB issued ASU No. 2015-11, "Inventory: Simplifying the Measurement of Inventory." ASU 2015-11 applies only to inventory for which cost is determined by methods other than last-in, first-out and the retail inventory method, which includes inventory that is measured using first-in, first-out or average cost. Inventory within the scope of this standard is required to be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The Company adopted ASU 2015-11 effective January 1, 2017. The adoption of this standard did not have a material impact on the Company's consolidated financial statements and related disclosures. Recently Issued Accounting Standards In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging," that was created to better align accounting rules with a company’s risk management activities, better reflect the economic results of hedging in the financial statements, and simplify hedge accounting treatment. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. For cash flow hedges existing at the adoption date, the standard requires adoption on a modified retrospective basis with a cumulative-effect adjustment to the consolidated balance sheet as of the beginning of the year of adoption. The amendments to presentation guidance and disclosure requirements are required to be adopted prospectively. The Company is currently evaluating the impact of the standard on its consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory." ASU 2016-16 clarifies the accounting for the current and deferred income taxes for an intra-entity transfer of an asset other than inventory. ASU 2016-16 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. The Company does not believe the adoption of ASU 2016-16 will have a material impact on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, "Leases." ASU 2016-02 requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. It will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018 and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact of the pending adoption of ASU 2016-02 on its consolidated financial statements, and currently expects that most of its operating lease commitments will be subject to the new standard and recognized as operating lease liabilities and right-of-use assets upon its adoption of ASU 2016-02, which will increase the total assets and total liabilities that the Company reports relative to such amounts prior to adoption. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers," which provides guidance for revenue recognition. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new guidance was originally effective for annual reporting periods beginning after December 15, 2016, including interim periods within those annual reporting periods. In July 2015, the FASB voted to defer the effective date of the new accounting guidance related to revenue recognition by one year to December 17, 2017 for annual reporting periods beginning after that date and permitted early adoption of the standard, but not before the original effective date of December 15, 2016. The standard will be effective for the Company beginning in the first quarter of 2018. The Company will adopt the standard using the modified retrospective method. The Company primarily derives its revenue from product sales. The adoption is not expected to have a material effect on the timing of recognition or measurement of revenue from the Company’s product sales. The Company also derives revenue from sales of connected robots, which represent arrangements with multiple performance obligations consisting of the robot, the iRobot Home app, potential future unspecified software upgrades and cloud services. ASU 2014-09 requires revenue to be allocated amongst material performance obligations based on stand-alone selling price and recognized based on the transfer of control of the material performance obligations. It is the Company’s position that the app, upgrades and cloud services related to the current offerings constitute a single immaterial performance obligation and therefore, the revenue associated with the robot and services will be recognized upon transfer of control to the customer. The Company's product sales are typically subject to limited rights of return, rebates, discounts and promotions and price protection. Accordingly, the Company reduces revenue for its estimates of allowances for these rights of return, rebates, discounts and promotions and price protection at the time the related sale is recorded based on contractual term, future expectation and historical experience. The Company does not expect that there will be material changes to the recognition of these allowances, and that these will continue to be recorded at the time the related revenue is recorded for the sales. The Company does expect that upon adoption of the standard, certain compliance-related charges will be estimated and recorded as a reduction of revenue at the time of sale, rather than upon resolution of the validity of the charges, but expects the impact of this to be immaterial to revenue. The Company does not expect the provisions of the new standard to impact the manner in which it treats certain costs to fulfill contracts (i.e., shipping and handling costs) and costs to acquire new contracts (i.e., commissions). Under the new standard, the Company will elect the practical expedient on shipping and handling costs and continue to treat these costs as fulfillment costs and expense as incurred. Further, commissions will continue to be expensed as incurred as the impact to the consolidated financial statements is immaterial. The new standard will also result in enhanced revenue related disclosures. 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 Accoun27

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 30, 2017
Accounting Policies [Abstract]
Components of available for sale securities	The fair value of investments is determined based on quoted market prices at the reporting date for those instruments. As of December 30, 2017 and December 31, 2016 , investments consisted of: December 30, December 31, Cost Fair Cost Fair (In thousands) Corporate and government bonds $ 37,767 $ 37,225 $ 40,439 $ 39,930 Total short term investments $ 37,767 $ 37,225 $ 40,439 $ 39,930
Activity related to allowance for doubtful accounts	Activity related to accounts receivable allowances was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Allowance for product returns Balance at beginning of period $ 27,673 $ 25,992 $ 27,449 Acquired balance 6,088 — — Provision 54,981 33,992 27,432 Deduction (43,831 ) (28,826 ) (21,979 ) Other adjustments (2,218 ) (3,485 ) (6,910 ) Balance at end of period $ 42,693 $ 27,673 $ 25,992 Allowance for discounts and promotions Balance at beginning of period $ 22,108 $ 23,005 $ 10,749 Acquired balance 11,932 — — Provision 107,390 45,869 39,482 Deduction (79,652 ) (46,610 ) (26,587 ) Other adjustments (3,567 ) (156 ) (639 ) Balance at end of period $ 58,211 $ 22,108 $ 23,005 Allowance for price protection Balance at beginning of period $ 1,550 $ — $ — Acquired balance — — — Provision 3,215 1,550 — Deduction (1,617 ) — — Other adjustments — — — Balance at end of period $ 3,148 $ 1,550 $ — Allowance for doubtful accounts Balance at beginning of period $ 29 $ 33 $ 67 Acquired balance 248 — — Provision 1 — — Deduction (2 ) (4 ) (34 ) Other adjustments — — — Balance at end of period $ 276 $ 29 $ 33
Property and equipment	Depreciation is computed using the straight-line method over the estimated useful lives as follows: Estimated Useful Life Computer and research equipment 2-5 years Furniture 5 Machinery 2-5 Tooling 2-5 Business applications software 5-7 Capital leases and leasehold improvements Lesser of economic benefit period or term of lease Property and equipment consists of the following at: December 30, December 31, (In thousands) Computer and equipment $ 10,669 $ 7,378 Furniture 4,120 2,906 Machinery 14,202 9,154 Tooling 31,783 20,487 Leasehold improvements 26,136 21,383 Business applications software 12,757 9,471 99,667 70,779 Less: accumulated depreciation 55,088 43,247 $ 44,579 $ 27,532
Basic and diluted net income per share	The following table presents the calculation of both basic and diluted net income per share: Fiscal Year Ended December 30, December 31, January 2, Net income $ 50,964 $ 41,939 $ 44,130 Weighted-average shares outstanding 27,611 27,698 29,550 Dilutive effect of employee stock options and restricted shares 1,142 594 557 Diluted weighted-average shares outstanding 28,753 28,292 30,107 Basic income per share $ 1.85 $ 1.51 $ 1.49 Diluted income per share $ 1.77 $ 1.48 $ 1.47

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 30, 2017
Business Combinations [Abstract]
Schedule of allocation of purchase price	The following table summarizes the final allocation of the purchase price (in thousands): Cash $ 125 Accounts receivable, net (1) (5,496 ) Inventory 18,290 Other assets 2,065 Deferred tax assets, net 409 Goodwill — Intangible assets 8,640 Total assets acquired 24,033 Accrued expenses and other current liabilities (4,450 ) Other liabilities (691 ) Total liabilities assumed (5,141 ) Net assets acquired $ 18,892 Gain on business acquisition (2,243 ) Total purchase price $ 16,649 (1) The accounts receivable balance reflects reserves for product returns, discounts and promotions assumed as part of the acquisition. The following table summarizes the preliminary allocation of the purchase price (in thousands): Cash $ 37,981 Accounts receivable 21,426 Inventory 36,304 Goodwill 79,558 Intangible assets 36,597 Other assets 2,456 Total assets 214,322 Accounts payable (29,391 ) Accrued expenses (3,376 ) Deferred tax liabilities (10,833 ) Other liabilities (645 ) Total liabilities assumed (44,245 ) Net assets acquired $ 170,077
Schedule of acquired intangible assets	The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives: Useful Life Fair Value (in thousands) Reacquired distribution rights 2.25 years $ 29,296 Customer relationships 14 years 7,029 Non-competition agreements 3 years 272 Total $ 36,597 The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives: Useful Life Fair Value (in thousands) Customer relationships 13 years $ 4,490 Reacquired distribution rights 9 months 4,150 Total $ 8,640
Schedule of pro forma results	The following table shows unaudited pro forma results of operations as if we had acquired Robopolis on January 3, 2016 (dollars in thousands, except per share amounts): Fiscal Year Ended December 30, December 31, Revenue $ 901,612 $ 718,917 Net income $ 51,887 $ 53,320 Net income per share: Basic income per share $ 1.88 $ 1.93 Diluted income per share $ 1.80 $ 1.88

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 30, 2017
Inventory Disclosure [Abstract]
Inventory	Inventory consists of the following at: December 30, December 31, (In thousands) Raw materials $ 4,036 $ 4,717 Finished goods 102,896 45,861 $ 106,932 $ 50,578

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 30, 2017
Property, Plant and Equipment [Abstract]
Property and equipment	Depreciation is computed using the straight-line method over the estimated useful lives as follows: Estimated Useful Life Computer and research equipment 2-5 years Furniture 5 Machinery 2-5 Tooling 2-5 Business applications software 5-7 Capital leases and leasehold improvements Lesser of economic benefit period or term of lease Property and equipment consists of the following at: December 30, December 31, (In thousands) Computer and equipment $ 10,669 $ 7,378 Furniture 4,120 2,906 Machinery 14,202 9,154 Tooling 31,783 20,487 Leasehold improvements 26,136 21,383 Business applications software 12,757 9,471 99,667 70,779 Less: accumulated depreciation 55,088 43,247 $ 44,579 $ 27,532

Goodwill and other intangible31

Goodwill and other intangible assets (Tables)	12 Months Ended
	Dec. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The following table summarizes the activity in the carrying amount of goodwill for fiscal years 2017 and 2016: (In thousands) Balance as of January 2, 2016 $ 48,751 Divestiture (1) (7,710 ) Balance as of December 31, 2016 41,041 Acquisitions (Note 3) 79,558 Effect of foreign currency translation 841 Balance as of December 30, 2017 $ 121,440 (1) In April 2016, the Company completed the sale of its defense and security business unit and therefore the goodwill balance assigned to the defense and security business unit was written off during the three months ended July 2, 2016.
Other intangible assets	Intangible assets at December 30, 2017 and December 31, 2016 consisted of the following: December 30, 2017 December 31, 2016 Cost Accumulated Amortization Net Cost Accumulated Amortization Net (In thousands) Completed technology $ 26,900 $ 18,150 $ 8,750 $ 26,900 $ 14,693 $ 12,207 Tradename 100 100 — 100 100 — Customer relationships 11,594 418 11,176 — — — Reacquired distribution rights 33,760 9,226 24,534 — — — Non-competition agreements 275 23 252 — — — Total $ 72,629 $ 27,917 $ 44,712 $ 27,000 $ 14,793 $ 12,207
Estimated future amortization expense related to current intangible assets	The estimated future amortization expense related to current intangible assets in each of the five succeeding fiscal years is expected to be as follows: (In thousands) 2018 $ 19,767 2019 13,188 2020 1,950 2021 1,714 2022 1,489 Thereafter 6,604 Total $ 44,712

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 30, 2017
Accrued Liabilities, Current [Abstract]
Components of accrued expenses	Accrued expenses consist of the following at: December 30, December 31, (In thousands) Accrued bonus 20,443 14,226 Accrued warranty 11,264 8,464 Accrued other compensation 9,071 6,789 Accrued sales and other taxes 7,256 422 Accrued federal and state income taxes 7,110 1,059 Accrued sales and marketing 3,299 404 Accrued direct fulfillment costs 1,885 1,722 Accrued customer deposits 1,324 1,171 Accrued accounting fees 1,221 686 Accrued rent — 327 Accrued other 10,774 5,599 $ 73,647 $ 40,869

Derivative Instruments and He33

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of fair values of derivative instruments	The fair values of derivative instruments are as follows: Fair Value Classification December 30, 2017 December 31, 2016 (In thousands) Derivatives not designated as hedging instruments: Foreign currency option contracts Other current assets $ — $ 180 Foreign currency forward contracts Other current assets 413 — Foreign currency forward contracts Accrued expenses 221 43 Derivatives designated as cash flow hedges: Foreign currency forward contracts Other current assets $ 488 $ — Foreign currency forward contracts Other assets 116 — Foreign currency forward contracts Accrued expenses 279 —
Schedule of derivative instruments gain (loss)	Gains (losses) associated with derivative instruments not designated as hedging instruments are as follows: Fiscal year ended Classification December 30, 2017 December 31, 2016 (In thousands) Gain (loss) recognized in income Other income, net $ (444 ) $ 29 The following tables reflect the effect of foreign exchange forward contracts that are designated as cash flow hedging instruments for the years ended December 30, 2017 and December 31, 2016 (in thousands): Effective Portion Ineffective Portion Gain (loss) recognized in OCI on Derivative (1) Gain (loss) reclassified from accumulated OCI into income (2) Gain (loss) recognized in income (3) Fiscal year ended Fiscal year ended Fiscal year ended December 30, 2017 December 31, 2016 Classification December 30, 2017 December 31, 2016 Classification December 30, 2017 December 31, 2016 Foreign currency forward contracts $ 584 $ — Revenue $ 320 $ — Other income, net $ (5 ) $ — Cost of revenue $ (63 ) $ — (1) The amount represents the change in fair value of derivative contracts due to changes in spot rates. (2) The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings. (3) The amount represents the change in fair value of derivative contracts due to changes in the forward rates. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities measured at fair value on a recurring basis	The Company’s financial assets and liabilities measured at fair value on a recurring basis at December 30, 2017 , were as follows: Fair Value Measurements as of December 30, 2017 Description Level 1 Level 2 (1) Level 3 (In thousands) Assets: Money market funds $ 3,165 $ — $ — Corporate and government bonds — 37,225 — Derivative instruments (Note 10) — 1,017 — Total assets measured at fair value $ 3,165 $ 38,242 $ — Liabilities: Derivative instruments (Note 10) $ — $ 500 $ — Total liabilities measured at fair value $ — $ 500 $ — The Company’s financial assets and liabilities measured at fair value on a recurring basis at December 31, 2016 , were as follows: Fair Value Measurements as of December 31, 2016 Description Level 1 Level 2 (1) Level 3 (In thousands) Assets: Money market funds $ 156,980 $ — $ — Corporate and government bonds — 39,930 — Derivative instruments (Note 10) — 180 — Total assets measured at fair value $ 156,980 $ 40,110 $ — Liabilities: Derivative instruments (Note 10) $ — $ 43 $ — Total liabilities measured at fair value $ — $ 43 $ — (1) Level 2 fair value estimates are based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

(Tables)

(Tables)	12 Months Ended
	Dec. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of stock option plan activity	The following table summarizes stock option activity for fiscal years 2017, 2016 and 2015: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value(1) Outstanding at December 27, 2014 1,473,320 $ 22.89 Granted 323,104 32.58 Exercised (390,085 ) 16.57 Canceled (118,789 ) 28.41 Outstanding at January 2, 2016 1,287,550 $ 26.73 Granted 314,770 38.03 Exercised (456,498 ) 20.47 Canceled (57,648 ) 33.28 Outstanding at December 31, 2016 1,088,174 $ 32.27 Granted 10,975 57.33 Exercised (367,267 ) 28.79 Canceled (18,928 ) 36.72 Outstanding at December 30, 2017 712,954 $ 34.34 4.27 years $30.2 million Vested and expected to vest at December 30, 2017 712,954 $ 34.34 4.27 years $30.2 million Exercisable as of December 30, 2017 399,163 $ 32.10 3.62 years $17.8 million _________________________ (1) The aggregate intrinsic value on the table above represents the difference between the Company's closing stock price on December 30, 2017 of $76.70 and the exercise price of the underlying in-the-money option.
Fair value of each option grant computed on the grant date	The fair value of each option grant for the fiscal years ended December 30, 2017 , December 31, 2016 , and January 2, 2016 was computed on the grant date using the Black-Scholes option-pricing model with the following assumptions: Fiscal Year Ended December 30, December 31, January 2, Risk-free interest rate 2.11% 1.17% — 1.89% 1.47% — 1.75% Expected dividend yield — — — Expected life 4.01 years 4.01 — 4.03 years 3.98 — 4.02 years Expected volatility 38.0% 38.9% — 42.1% 46.5% — 52.4%
Summary of information about stock options outstanding	Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Remaining Contractual Life Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 3.54 - $ 26.59 113,447 1.90 years $ 23.00 113,447 $ 23.00 29.60 - 32.38 109,187 4.54 31.13 55,396 31.33 33.14 - 33.14 108,113 5.19 33.14 39,085 33.14 33.29 - 34.30 116,942 4.06 34.01 66,770 33.99 35.43 - 37.08 58,858 3.52 35.72 49,232 35.60 37.62 - 37.62 99,370 5.44 37.62 31,467 37.62 39.09 - 39.09 37,589 5.69 39.09 9,434 39.09 43.35 - 43.35 29,605 3.18 43.35 27,178 43.35 57.33 - 57.33 10,975 6.19 57.33 — — 58.55 - 58.55 28,868 5.94 58.55 7,154 58.55 $ 3.54 - $58.55 712,954 4.27 years $ 34.34 399,163 $ 32.10
Activities relating to restricted stock awards	The following table summarizes the restricted stock unit activity for fiscal years 2017, 2016 and 2015: Number of Shares Underlying Restricted Stock Weighted Average Grant Date Fair Value Outstanding at December 27, 2014 880,138 $ 30.10 Granted 505,277 36.88 Vested (340,754 ) 29.13 Forfeited (110,784 ) 30.82 Outstanding at January 2, 2016 933,877 $ 31.42 Granted 458,237 37.93 Vested (358,018 ) 30.81 Forfeited (98,917 ) 32.13 Outstanding at December 31, 2016 935,179 $ 35.07 Granted 396,164 72.63 Vested (351,543 ) 33.73 Forfeited (41,347 ) 39.52 Outstanding at December 30, 2017 938,453 $ 51.24
Activities relating to performance based restricted stock units	The following table summarizes the performance based restricted stock unit activity for fiscal years 2017, 2016 and 2015: Number of Weighted Average Outstanding at December 27, 2014 29,717 $ 43.35 Granted 71,133 34.30 Vested — — Forfeited (10,358 ) 38.60 Outstanding at January 2, 2016 90,492 $ 36.78 Granted 82,085 33.36 Vested (5,625 ) 34.30 Forfeited (3,041 ) 34.30 Outstanding at December 31, 2016 163,911 $ 35.03 Granted 105,650 57.33 Vested (24,792 ) 43.35 Forfeited (2,708 ) 39.71 Outstanding at December 30, 2017 242,061 $ 43.97 _________________________ (1) Includes the target number of PSUs.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 30, 2017
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 December 30, 2017 : Operating Leases 2018 $ 6,361 2019 6,901 2020 6,506 2021 6,502 2022 6,498 Thereafter 39,839 Total minimum lease payments $ 72,607
Activity related to the warranty accrual	Activity related to the warranty accrual was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Balance at beginning of period $ 8,464 $ 6,907 $ 7,769 Liability assumed (1) 2,186 — — Provision 8,591 7,494 4,598 Warranty usage (2) (7,977 ) (5,937 ) (5,460 ) Balance at end of period $ 11,264 $ 8,464 $ 6,907 __________________________________ (1) Warranty assumed as part of the acquisition of the iRobot-related distribution business of Sales On Demand Corporation (see Note 3). (2) Warranty usage includes costs incurred for warranty obligations and, for the twelve month period ended December 31, 2016, the release of warranty liabilities associated with the divestiture of the defense and security business unit.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 30, 2017
Income Tax Disclosure [Abstract]
Schedule of income (loss) before provision for income taxes	Income (loss) before provision for income taxes was as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Domestic $ 71,382 $ 61,706 $ 62,391 Foreign 4,984 (345 ) 580 Income before income taxes $ 76,366 $ 61,361 $ 62,971
Components of income tax expense	The components of income tax expense were as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Current Federal $ 17,555 $ 17,639 $ 20,033 State 1,691 1,054 972 Foreign 7,355 310 121 Total current income tax provision 26,601 19,003 21,126 Deferred Federal $ 6,664 $ 781 $ (1,657 ) State (2,470 ) (95 ) (628 ) Foreign (5,393 ) (267 ) — Total deferred income tax provision (1,199 ) 419 (2,285 ) Total income tax provision $ 25,402 $ 19,422 $ 18,841
Reconciliation of the expected tax (benefit) expense	A reconciliation of the expected tax (benefit) expense computed by applying the federal statutory rate to income before income taxes to actual tax expense is as follows: Fiscal Year Ended December 30, December 31, January 2, (In thousands) Expected federal income tax $ 26,728 $ 21,476 $ 22,040 Miscellaneous permanent items 2,979 516 608 State taxes (net of federal benefit) 2,089 1,360 982 Federal and state credits (4,486 ) (2,233 ) (2,767 ) Change in valuation allowance 800 — — Domestic production activities deduction (1,528 ) (1,731 ) (2,145 ) Statute of limitation expirations of uncertain tax positions (106 ) (167 ) (194 ) Excess tax benefits relating to stock-based compensation (11,709 ) — — Tax Cuts and Jobs Act of 2017 11,861 — — Other (1,226 ) 201 317 $ 25,402 $ 19,422 $ 18,841
Components of net deferred tax assets	The components of net deferred tax assets were as follows: December 30, December 31, (In thousands) Deferred tax assets Reserves and accruals $ 24,315 $ 20,737 Tax credits 6,666 5,999 Property and equipment 1,382 1,934 Stock-based compensation 4,277 6,150 Net operating loss carryforwards 144 1,010 Valuation allowance (800 ) — Gross deferred tax assets 35,984 35,830 Deferred tax liabilities Intangible assets 13,419 4,530 Other 573 715 Gross deferred tax liabilities 13,992 5,245 Net deferred tax assets $ 21,992 $ 30,585
Schedule of adjustments to uncertain tax position	A summary of the Company’s adjustments to its gross unrecognized tax benefits in the current year is as follows: Fiscal Year Ended December 30, 2017 December 31, January 2, (in thousands) Balance at beginning of period $ 5,146 $ 6,616 $ 2,491 Increase for tax positions related to the current year 580 2,851 786 Increase (decrease) for tax positions related to prior years (523 ) (4,224 ) 3,533 Decreases for settlements with applicable taxing authorities — — — Decreases for lapses of statute of limitations (613 ) (97 ) (194 ) Balance at end of period $ 4,590 $ 5,146 $ 6,616

Quarterly Information (Unaudi38

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 30, 2017
Quarterly Financial Information Disclosure [Abstract]
Details of Quarterly Information (Unaudited)	The following information has been derived from unaudited consolidated financial statements that, in the opinion of management, include all recurring adjustments necessary for a fair statement of such information (dollars in thousands, except per share amounts): Fiscal Quarter Ended December 30, September 30, July 1, April 1, December 31, October 1, July 2, April 2, (In thousands, except per share amounts) Revenue $ 326,897 $ 205,399 $ 183,148 $ 168,467 $ 212,494 $ 168,610 $ 148,696 $ 130,804 Gross margin 153,542 102,383 89,891 87,343 106,642 81,060 69,652 61,961 Net income 4,620 22,082 7,903 16,359 13,681 19,512 4,814 3,932 Diluted earnings per share $ 0.16 $ 0.76 $ 0.27 $ 0.58 $ 0.49 $ 0.70 $ 0.17 $ 0.13

- Short Term Investments (Detai

- Short Term Investments (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Components of available for sale securities
Total short term investments, Cost	$ 37,767	$ 40,439
Total short term investments, Fair Market Value	37,225	39,930
Corporate and government bonds
Components of available for sale securities
Total short term investments, Cost	37,767	40,439
Total short term investments, Fair Market Value	$ 37,225	$ 39,930

- Accounts Receivable Allowance

- Accounts Receivable Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Allowance for product returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 27,673	$ 25,992	$ 27,449
Acquired balance	6,088	0	0
Provision	54,981	33,992	27,432
Deduction	(43,831)	(28,826)	(21,979)
Other adjustments	(2,218)	(3,485)	(6,910)
Balance at end of period	42,693	27,673	25,992
Allowance for discounts and promotions
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	22,108	23,005	10,749
Acquired balance	11,932	0	0
Provision	107,390	45,869	39,482
Deduction	(79,652)	(46,610)	(26,587)
Other adjustments	(3,567)	(156)	(639)
Balance at end of period	58,211	22,108	23,005
Allowance for price protection
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	1,550	0	0
Acquired balance	0	0	0
Provision	3,215	1,550
Deduction	(1,617)	0	0
Other adjustments	0	0	0
Balance at end of period	3,148	1,550	0
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	29	33	67
Acquired balance	248	0	0
Provision	1	0
Deduction	(2)	(4)	(34)
Other adjustments	0	0	0
Balance at end of period	$ 276	$ 29	$ 33

- Property and Equipment (Detai

- Property and Equipment (Details)	12 Months Ended
	Dec. 30, 2017
Leasehold improvements
Property, Plant and Equipment [Line Items]
Capital Leases and Leasehold Improvements Terms	Lesser of economic benefit period or term of lease
Furniture
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Minimum | Computer and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Minimum | Machinery
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Minimum | Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Minimum | Business applications software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum | Computer and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum | Machinery
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum | Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum | Business applications software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

- Net Income Per Share (Details

- Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Basic and Diluted Net Income Per Share
Net income	$ 4,620	$ 22,082	$ 7,903	$ 16,359	$ 13,681	$ 19,512	$ 4,814	$ 3,932	$ 50,964	$ 41,939	$ 44,130
Weighted-average shares outstanding									27,611	27,698	29,550
Dilutive effect of employee stock options and restricted shares									1,142	594	557
Diluted weighted-average shares outstanding									28,753	28,292	30,107
Basic income per share (in dollars per share)									$ 1.85	$ 1.51	$ 1.49
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.76	$ 0.27	$ 0.58	$ 0.49	$ 0.70	$ 0.17	$ 0.13	$ 1.77	$ 1.48	$ 1.47

Summary of Significant Accoun43

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2017	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Accounting Policies [Line Items]
Cash equivalents	$ 3,200	$ 3,200	$ 157,000
Cost and equity method investments	14,200	14,200	12,900
Capitalized computer software	12,800	12,800	9,500
Advertising Expense		91,800	64,400	$ 54,700
Valuation allowance	800	$ 800	$ 0
Tax Cuts and Jobs Act of 2017, income tax expense (benefit), transition tax fior accumulated foreign earnings	3,000
Tax Cuts and Jobs Act of 2017, income tax expense (benefit)	11,900
Tax Cuts and Jobs Act of 2017, income tax expense (benefit), remeasurement of certain deferred tax assets and liabilities	8,900
Antidilutive securities excluded from computation of earnings per share (in shares)		0	0.4	0.5
Minimum
Accounting Policies [Line Items]
Warrant term		1 year
Maximum
Accounting Policies [Line Items]
Warrant term		2 years
Customer Concentration Risk | Accounts Receivable | 1 Customer
Accounting Policies [Line Items]
Concentration risk percentage		11.50%
Customer Concentration Risk | Accounts Receivable | Three Customers
Accounting Policies [Line Items]
Concentration risk percentage			43.90%
Customer Concentration Risk | Accounts Receivable | Two Customers Secured Balance With Guaranteed Letters Of Credit
Accounting Policies [Line Items]
Concentration risk percentage			32.50%
Customer Concentration Risk | Revenue | 1 Customer
Accounting Policies [Line Items]
Concentration risk percentage		13.50%	10.40%
Customer Concentration Risk | Revenue | Sales On Demand Corporation (SODC)
Accounting Policies [Line Items]
Concentration risk percentage			12.90%	13.30%
Customer Concentration Risk | Revenue | Robopolis SAS
Accounting Policies [Line Items]
Concentration risk percentage			12.30%	12.70%
Business applications software
Accounting Policies [Line Items]
Amortization expense		$ 1,500	$ 400	$ 700
Allowance for product returns
Accounting Policies [Line Items]
Valuation allowances and reserves	42,693	42,693	27,673	25,992	$ 27,449
Allowance for discounts and promotions
Accounting Policies [Line Items]
Valuation allowances and reserves	58,211	58,211	22,108	23,005	10,749
Allowance for price protection
Accounting Policies [Line Items]
Valuation allowances and reserves	$ 3,148	$ 3,148	$ 1,550	$ 0	$ 0

Business Combinations - Robopol

Business Combinations - Robopolis Acquisition (Details) - USD ($) $ in Thousands	Oct. 02, 2017	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Business Acquisition [Line Items]
Payments to acquire business net of cash acquired		$ 148,765	$ 0	$ 0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill		$ 121,440	$ 41,041	$ 48,751
Robopolis
Business Acquisition [Line Items]
Payments to acquire business net of cash acquired	$ 170,100
Cash acquired from acquisition	38,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash	37,981
Accounts receivable	21,426
Inventory	36,304
Goodwill	79,558
Intangible assets	36,597
Other assets	2,456
Total assets	214,322
Accounts payable	(29,391)
Accrued expenses	(3,376)
Deferred tax liabilities	(10,833)
Other liabilities	(645)
Total liabilities assumed	44,245
Net assets acquired	170,077
Intangible assets acquired, fair value	$ 36,597
Discount rate	14.50%
Reacquired distribution rights | Robopolis
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Intangible assets, useful life	2 years 3 months
Intangible assets acquired, fair value	$ 29,296
Customer relationships | Robopolis
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Intangible assets, useful life	14 years
Intangible assets acquired, fair value	$ 7,029
Non-competition agreements | Robopolis
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Intangible assets, useful life	3 years
Intangible assets acquired, fair value	$ 272

Business Combinations - Sales O

Business Combinations - Sales On Demand Corporation Acquisition (Details) - USD ($) $ in Thousands	Apr. 03, 2017	Sep. 30, 2017	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill			$ 121,440	$ 41,041	$ 48,751
Gain on business acquisition			$ (2,243)	$ 0	$ 0
Sales On Demand Corporation
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 16,649
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash	125
Accounts receivable	(5,496)
Inventory	18,290
Other assets	2,065
Deferred tax assets, net	409
Goodwill	0
Intangible assets	8,640
Total assets	24,033
Accrued expenses and other current liabilities	(4,450)
Other liabilities	(691)
Total liabilities assumed	5,141
Net assets acquired	18,892
Gain on business acquisition		$ (2,243)
Intangible assets acquired, fair value	$ 8,640
Sales On Demand Corporation | Customer relationships
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Intangible assets, useful life	13 years
Intangible assets acquired, fair value	$ 4,490
Sales On Demand Corporation | Reacquired distribution rights
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Intangible assets, useful life	9 months
Intangible assets acquired, fair value	$ 4,150

Business Combinations - Pro For

Business Combinations - Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Revenue	$ 901,612	$ 718,917
Net income	$ 51,887	$ 53,320
Basic income per share (in dollars per share)	$ 1.88	$ 1.93
Diluted income per share (in dollars per share)	$ 1.80	$ 1.88

Divestiture (Details)

Divestiture (Details) $ in Millions	Apr. 04, 2016USD ($)
Discontinued Operations and Disposal Groups [Abstract]
Disposal Group, Including Discontinued Operation, Consideration	$ 24.5
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 0.4

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Inventory
Raw materials	$ 4,036	$ 4,717
Finished goods	102,896	45,861
Total	$ 106,932	$ 50,578

Property and Equipment 1 (Detai

Property and Equipment 1 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 99,667	$ 70,779
Less: accumulated depreciation	55,088	43,247
Property, Plant and Equipment, Net	44,579	27,532
Depreciation	12,300	10,000	$ 11,400
Computer and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	10,669	7,378
Furniture
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,120	2,906
Machinery
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,202	9,154
Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	31,783	20,487
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	26,136	21,383
Business applications software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 12,757	$ 9,471

Goodwill and other intangible50

Goodwill and other intangible assets - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill	$ 41,041	$ 48,751
Divestiture		(7,710)
Acquisitions (Note 3)	79,558
Effect of foreign currency translation	841
Goodwill	$ 121,440	$ 41,041

Goodwill and other intangible51

Goodwill and other intangible assets - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets, Net [Abstract]
Cost	$ 72,629	$ 27,000
Accumulated Amortization	27,917	14,793
Net	44,712	12,207
Completed technology
Finite-Lived Intangible Assets, Net [Abstract]
Cost	26,900	26,900
Accumulated Amortization	18,150	14,693
Net	8,750	12,207
Tradename
Finite-Lived Intangible Assets, Net [Abstract]
Cost	100	100
Accumulated Amortization	100	100
Net	0	0
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Cost	11,594	0
Accumulated Amortization	418	0
Net	11,176	0
Reacquired distribution rights
Finite-Lived Intangible Assets, Net [Abstract]
Cost	33,760	0
Accumulated Amortization	9,226	0
Net	24,534	0
Non-competition agreements
Finite-Lived Intangible Assets, Net [Abstract]
Cost	275	0
Accumulated Amortization	23	0
Net	$ 252	$ 0

Goodwill and other intangible52

Goodwill and other intangible assets - Future Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 13,100	$ 3,500	$ 3,500
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2,018	19,767
2,019	13,188
2,020	1,950
2,021	1,714
2,022	1,489
Thereafter	6,604
Net	$ 44,712	$ 12,207

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Components of accrued expenses
Accrued bonus	$ 20,443	$ 14,226
Accrued warranty	11,264	8,464
Accrued other compensation	9,071	6,789
Accrued sales and other taxes	7,256	422
Accrued federal and state income taxes	7,110	1,059
Accrued Marketing Costs, Current	3,299	404
Accrued direct fulfillment costs	1,885	1,722
Accrued customer deposits	1,324	1,171
Accrued accounting fees	1,221	686
Accrued rent	0	327
Accrued other	10,774	5,599
Accrued expenses, total	$ 73,647	$ 40,869

Working Capital Facilities (Det

Working Capital Facilities (Details) $ in Thousands	12 Months Ended
	Dec. 30, 2017USD ($)
Debt Disclosure [Abstract]
Letters of Credit Outstanding, Amount	$ 1,000
Revolving Line of Credit (Textual) [Abstract]
Maximum amount available for borrowing under credit facility	$ 75,000
Interest on loans under the credit facility	at either (1) LIBOR plus a margin, currently equal to 1.0%, based on the Company's ratio of indebtedness to Adjusted EBITDA (the "Eurodollar Rate"), or (2) the lender's base rate.
Interest rate above the LIBOR Daily Floating Rate or the Prime Rate of Lender under condition one	1.00%
Interest Rate Above the Federal Fund Rate Under Condition Two	0.50%
Interest rate above the LIBOR rate plus under condition two	1.00%
Termination date for all outstanding amount and credit facility	Dec. 20, 2018
Line of Credit Facility, Amount Outstanding	$ 0
Letter of credit facility, maximum borrowing	$ 5,000
Line of Credit Facility, Commitment Fee Percentage	1.50%

Derivative Instruments and He55

Derivative Instruments and Hedging Activities - Fair Value of Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 36,600	$ 8,100
Foreign currency option contracts | Derivatives not designated as hedging instruments: | Other current assets
Derivative, Fair Value, Net [Abstract]
Derivative Asset	0	180
Foreign currency forward contracts | Derivatives not designated as hedging instruments: | Other current assets
Derivative, Fair Value, Net [Abstract]
Derivative Asset	413	0
Foreign currency forward contracts | Derivatives not designated as hedging instruments: | Accrued expenses
Derivative, Fair Value, Net [Abstract]
Derivative Liability	221	43
Cash flow hedge | Derivatives designated as cash flow hedges:
Derivatives, Fair Value [Line Items]
Derivative notional amount	73,700	0
Cash flow hedge | Foreign currency forward contracts | Derivatives designated as cash flow hedges: | Other current assets
Derivative, Fair Value, Net [Abstract]
Derivative Asset	488	0
Cash flow hedge | Foreign currency forward contracts | Derivatives designated as cash flow hedges: | Other assets
Derivative, Fair Value, Net [Abstract]
Derivative Asset	116	0
Cash flow hedge | Foreign currency forward contracts | Derivatives designated as cash flow hedges: | Accrued expenses
Derivative, Fair Value, Net [Abstract]
Derivative Liability	$ 279	$ 0
Maximum | Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Derivative term	2 months
Maximum | Cash flow hedge | Derivatives designated as cash flow hedges:
Derivatives, Fair Value [Line Items]
Derivative term	14 months

Derivative Instruments and He56

Derivative Instruments and Hedging Activities - Gain (Loss) on Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Other income, net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income	$ (444)	$ 29
Foreign currency forward contracts | Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion, Gain (loss) recognized in OCI on Derivative	584	0
Foreign currency forward contracts | Revenue | Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion, Gain (loss) reclassified from accumulated OCI into income	320	0
Foreign currency forward contracts | Cost of revenue | Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion, Gain (loss) reclassified from accumulated OCI into income	(63)	0
Foreign currency forward contracts | Other income, net | Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Ineffective portion, Gain (loss) recognized in income	$ (5)	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Recurring - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Level 1
Assets:
Corporate and government bonds	$ 0	$ 0
Derivative instruments (Note 10)	0	0
Total assets measured at fair value	3,165	156,980
Liabilities:
Derivative instruments (Note 10)	0	0
Total liabilities measured at fair value	0	0
Level 1 | Money market funds
Assets:
Money market funds	3,165	156,980
Level 2
Assets:
Corporate and government bonds	37,225	39,930
Derivative instruments (Note 10)	1,017	180
Total assets measured at fair value	38,242	40,110
Liabilities:
Derivative instruments (Note 10)	500	43
Total liabilities measured at fair value	500	43
Level 2 | Money market funds
Assets:
Money market funds	0	0
Level 3
Assets:
Corporate and government bonds	0	0
Derivative instruments (Note 10)	0	0
Total assets measured at fair value	0	0
Liabilities:
Derivative instruments (Note 10)	0	0
Total liabilities measured at fair value	0	0
Level 3 | Money market funds
Assets:
Money market funds	$ 0	$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details)	Mar. 19, 2015USD ($)	Apr. 02, 2014USD ($)	Dec. 30, 2017USD ($)vote$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Jan. 02, 2016USD ($)shares	Mar. 01, 2016USD ($)	Dec. 28, 2015USD ($)shares
Equity [Abstract]
Preferred stock, shares authorized			5,000,000	5,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
Common stock, votes per share | vote			1
Stock repurchase program, authorized amount | $	$ 50,000,000	$ 50,000,000				$ 85,000,000	$ 40,000,000
Stock repurchase program, authorized amount (in shares)							1,000,000
Program commencement date	May 1, 2015	May 1, 2014
Program expiration date	Apr. 30, 2016	Apr. 30, 2015
Stock repurchases (in shares)			0	2,641,122	1,260,276
Stock repurchases | $			$ 0	$ 97,021,000	$ 37,393,000

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 30, 2017USD ($)planshares	Dec. 31, 2016USD ($)	Jan. 02, 2016USD ($)	May 20, 2015shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of plans | plan	3
Capital shares reserved for future issuance				3,100,000
Share conversion ratio	1.61
Number of shares available for grant	590,655
Share-based compensation expense | $	$ 19.8	$ 16	$ 14.2

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation not yet recognized, options	$ 4
Summary of stock option plan activity
Number of Shares, Beginning Balance	1,088,174	1,287,550	1,473,320
Number of Shares, Granted	10,975	314,770	323,104
Number of Shares, Exercised	(367,267)	(456,498)	(390,085)
Number of Shares, Canceled	(18,928)	(57,648)	(118,789)
Number of Shares, Ending Balance	712,954	1,088,174	1,287,550
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning Balance (in dollars per share)	$ 32.27	$ 26.73	$ 22.89
Weighted Average Exercise Price, Granted (in dollars per share)	57.33	38.03	32.58
Weighted Average Exercise Price, Exercised (in dollars per share)	28.79	20.47	16.57
Weighted Average Exercise Price, Canceled (in dollars per share)	36.72	33.28	28.41
Weighted Average Exercise Price, Ending Balance (in dollars per share)	$ 34.34	$ 32.27	$ 26.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares, Vested and expected to vest	712,954
Number of Shares, Exercisable	399,163
Weighted Average Exercise Price, Vested and expected to vest (in dollars per share)	$ 34.34
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 32.10
Weighted Average Remaining Contractual Term, Vested and expected to vest	4 years 3 months 8 days
Weighted Average Remaining Contractual Term, Ending Balance	4 years 3 months 8 days
Weighted Average Remaining Contractual Term, Exercisable	3 years 7 months 15 days
Aggregate Intrinsic Value, Ending Balance	$ 30.2
Aggregate Intrinsic Value, Vested and expected to vest	30.2
Aggregate Intrinsic Value, Exercisable	$ 17.8
Share price (in dollars per share)	$ 76.70
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Weighted average remaining recognition period	2 years 26 days
Employee Stock Option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum expiration period for options	5 years
Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum expiration period for options	10 years

Stock-Based Compensation - St61

Stock-Based Compensation - Stock Options Assumptions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, exercises in period, intrinsic value	$ 21.8	$ 10.3	$ 5.9
Fair value of each option grant computed on the grant date
Risk-free interest rate, minimum	2.11%	1.17%	1.47%
Risk-free interest rate, maximum	2.11%	1.89%	1.75%
Expected volatility, minimum	38.00%	38.90%	46.50%
Expected volatility, maximum	38.00%	42.10%	52.40%
Minimum
Fair value of each option grant computed on the grant date
Expected dividend rate	0.00%	0.00%	0.00%
Expected life	4 years 5 days	4 years 5 days	3 years 10 months 55 days
Maximum
Fair value of each option grant computed on the grant date
Expected dividend rate	0.00%	0.00%	0.00%
Expected life	4 years 5 days	4 years 11 days	4 years 9 days

Stock-Based Compensation - St62

Stock-Based Compensation - Stock Options Exercise Price Range (Details)	12 Months Ended
	Dec. 30, 2017$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$ 3.54
Range of Exercise Price, Maximum	$ 58.55
Number Outstanding | shares	712,954
Options Outstanding Weighted Average Remaining Contractual Life	4 years 3 months 8 days
Weighted Average Exercise Price	$ 34.34
Number Exercisable | shares	399,163
Weighted Average Exercise Price	$ 32.10
$ 3.54 - $ 26.59
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	3.54
Range of Exercise Price, Maximum	$ 26.59
Number Outstanding | shares	113,447
Options Outstanding Weighted Average Remaining Contractual Life	1 year 10 months 23 days
Weighted Average Exercise Price	$ 23
Number Exercisable | shares	113,447
Weighted Average Exercise Price	$ 23
29.60 - 32.38
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	29.60
Range of Exercise Price, Maximum	$ 32.38
Number Outstanding | shares	109,187
Options Outstanding Weighted Average Remaining Contractual Life	4 years 6 months 16 days
Weighted Average Exercise Price	$ 31.13
Number Exercisable | shares	55,396
Weighted Average Exercise Price	$ 31.33
33.14 - 33.14
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	33.14
Range of Exercise Price, Maximum	$ 33.14
Number Outstanding | shares	108,113
Options Outstanding Weighted Average Remaining Contractual Life	5 years 2 months 10 days
Weighted Average Exercise Price	$ 33.14
Number Exercisable | shares	39,085
Weighted Average Exercise Price	$ 33.14
33.29 - 34.30
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	33.29
Range of Exercise Price, Maximum	$ 34.30
Number Outstanding | shares	116,942
Options Outstanding Weighted Average Remaining Contractual Life	4 years 22 days
Weighted Average Exercise Price	$ 34.01
Number Exercisable | shares	66,770
Weighted Average Exercise Price	$ 33.99
35.43 - 37.08
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	35.43
Range of Exercise Price, Maximum	$ 37.08
Number Outstanding | shares	58,858
Options Outstanding Weighted Average Remaining Contractual Life	3 years 6 months 9 days
Weighted Average Exercise Price	$ 35.72
Number Exercisable | shares	49,232
Weighted Average Exercise Price	$ 35.60
37.62 - 37.62
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	37.62
Range of Exercise Price, Maximum	$ 37.62
Number Outstanding | shares	99,370
Options Outstanding Weighted Average Remaining Contractual Life	5 years 5 months 10 days
Weighted Average Exercise Price	$ 37.62
Number Exercisable | shares	31,467
Weighted Average Exercise Price	$ 37.62
39.09 - 39.09
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	39.09
Range of Exercise Price, Maximum	$ 39.09
Number Outstanding | shares	37,589
Options Outstanding Weighted Average Remaining Contractual Life	5 years 8 months 10 days
Weighted Average Exercise Price	$ 39.09
Number Exercisable | shares	9,434
Weighted Average Exercise Price	$ 39.09
43.35 - 43.35
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	43.35
Range of Exercise Price, Maximum	$ 43.35
Number Outstanding | shares	29,605
Options Outstanding Weighted Average Remaining Contractual Life	3 years 2 months 6 days
Weighted Average Exercise Price	$ 43.35
Number Exercisable | shares	27,178
Weighted Average Exercise Price	$ 43.35
57.33 - 57.33
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	57.33
Range of Exercise Price, Maximum	$ 57.33
Number Outstanding | shares	10,975
Options Outstanding Weighted Average Remaining Contractual Life	6 years 2 months 8 days
Weighted Average Exercise Price	$ 57.33
Number Exercisable | shares	0
Weighted Average Exercise Price	$ 0
58.55 - 58.55
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	58.55
Range of Exercise Price, Maximum	$ 58.55
Number Outstanding | shares	28,868
Options Outstanding Weighted Average Remaining Contractual Life	5 years 11 months 10 days
Weighted Average Exercise Price	$ 58.55
Number Exercisable | shares	7,154
Weighted Average Exercise Price	$ 58.55

Stock-Based Compensation - RSUs

Stock-Based Compensation - RSUs and PSUs (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Share price (in dollars per share)	$ 76.70
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Compensation cost not yet recognized	$ 39.3
Weighted average remaining recognition period	2 years 6 months 7 days
Activities relating to restricted stock awards
Number of Shares Underlying Restricted Stock, Beginning Balance	935,179	933,877	880,138
Number of Shares Underlying Restricted Stock, Granted	396,164	458,237	505,277
Number of Shares Underlying Restricted Stock, Vested	(351,543)	(358,018)	(340,754)
Number of Shares Underlying Restricted Stock, Forfeited	(41,347)	(98,917)	(110,784)
Number of Shares Underlying Restricted Stock, Ending Balance	938,453	935,179	933,877
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share)	$ 35.07	$ 31.42	$ 30.10
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	72.63	37.93	36.88
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	33.73	30.81	29.13
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)	39.52	32.13	30.82
Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share)	$ 51.24	$ 35.07	$ 31.42
Outstanding, aggregate intrinsic value	$ 72
Outstanding, weighted average remaining contractual term	1 year 6 months
Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Compensation cost not yet recognized	$ 5.6
Weighted average remaining recognition period	1 year 4 months 21 days
Activities relating to restricted stock awards
Number of Shares Underlying Restricted Stock, Beginning Balance	163,911	90,492	29,717
Number of Shares Underlying Restricted Stock, Granted	105,650	82,085	71,133
Number of Shares Underlying Restricted Stock, Vested	(24,792)	(5,625)	0
Number of Shares Underlying Restricted Stock, Forfeited	(2,708)	(3,041)	(10,358)
Number of Shares Underlying Restricted Stock, Ending Balance	242,061	163,911	90,492
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share)	$ 35.03	$ 36.78	$ 43.35
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	57.33	33.36	34.30
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	43.35	34.30	0
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)	39.71	34.30	38.60
Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share)	$ 43.97	$ 35.03	$ 36.78
Outstanding, aggregate intrinsic value	$ 18.6
Outstanding, weighted average remaining contractual term	1 year 4 months 21 days
Performance Based Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights percentage	0.00%
Performance Based Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights percentage	200.00%

Stock-Based Compensation - ESPP

Stock-Based Compensation - ESPP (Details) - USD ($)	1 Months Ended
	May 31, 2017	May 20, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capital shares reserved for future issuance		3,100,000
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capital shares reserved for future issuance	700,000
Offering period	6 months
Maximum dollar amount	$ 4,000
Maximum number of shares per employee	1,000
Purchase price of common stock percent	85.00%
Employee Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of salary	1.00%
Employee Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of salary	15.00%

Commitments and Contingencies65

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Commitments and Contingencies Disclosure [Abstract]
Rental expense under operating leases	$ 8,900	$ 6,000	$ 4,900
Summary of future minimum rental payments under operating leases
2,018	6,361
2,019	6,901
2,020	6,506
2,021	6,502
2,022	6,498
Thereafter	39,839
Total minimum lease payments	72,607
Contractual Obligation	$ 74,400

Commitments and Contingencies66

Commitments and Contingencies (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Activity related to the warranty accrual
Balance at beginning of period	$ 8,464	$ 6,907	$ 7,769
Liability assumed	2,186		0
Provision	8,591	7,494	4,598
Warranty usage	(7,977)	(5,937)	(5,460)
Balance at end of period	$ 11,264	$ 8,464	$ 6,907

Employee Benefits (Details)

Employee Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Retirement Benefits [Abstract]
Defined Contribution Plan, Cost	$ 2.4	$ 1.7	$ 1.8
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3.00%

Income Taxes - Income (Loss) Be

Income Taxes - Income (Loss) Before Provision For Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Income Tax Disclosure [Abstract]
Domestic	$ 71,382	$ 61,706	$ 62,391
Foreign	4,984	(345)	580
Income before income taxes	$ 76,366	$ 61,361	$ 62,971

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Current
Federal	$ 17,555	$ 17,639	$ 20,033
State	1,691	1,054	972
Foreign	7,355	310	121
Total current income tax provision	26,601	19,003	21,126
Deferred
Federal	6,664	781	(1,657)
State	(2,470)	(95)	(628)
Foreign	(5,393)	(267)	0
Total deferred income tax provision	(1,199)	419	(2,285)
Total income tax provision	$ 25,402	$ 19,422	$ 18,841

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Reconciliation of the expected tax (benefit) expense
Expected federal income tax	$ 26,728	$ 21,476	$ 22,040
Miscellaneous permanent items	2,979	516	608
State taxes (net of federal benefit)	2,089	1,360	982
Federal and state credits	(4,486)	(2,233)	(2,767)
Change in valuation allowance	800	0	0
Domestic production activities deduction	(1,528)	(1,731)	(2,145)
Statute of limitation expirations of uncertain tax positions	(106)	(167)	(194)
Excess tax benefits relating to stock-based compensation	(11,709)	0	0
Tax Cuts and Jobs Act of 2017	11,861	0	0
Other	(1,226)	201	317
Total expected tax (benefits) expenses	$ 25,402	$ 19,422	$ 18,841

Income Taxes - Net Deferred Tax

Income Taxes - Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Deferred tax assets
Reserves and accruals	$ 24,315	$ 20,737
Tax credits	6,666	5,999
Property and equipment	1,382	1,934
Stock-based compensation	4,277	6,150
Net operating loss carryforwards	144	1,010
Valuation allowance	(800)	0
Gross deferred tax assets	35,984	35,830
Deferred tax liabilities
Intangible assets	13,419	4,530
Other	573	715
Reserves and accruals	13,992	5,245
Deferred Tax Assets, Net	$ 21,992	$ 30,585

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Company's adjustments to its uncertain tax position
Balance at beginning of period	$ 5,146	$ 6,616	$ 2,491
Increase for tax positions related to the current year	580	2,851	786
Decrease for tax positions related to prior years	(523)	(4,224)
Increase for tax positions related to prior years			3,533
Decreases for settlements with applicable taxing authorities	0	0	0
Decreases for lapses of statute of limitations	(613)	(97)	(194)
Balance at end of period	$ 4,590	$ 5,146	$ 6,616

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Tax Credit Carryforward [Line Items]
Tax Cuts and Jobs Act of 2017, income tax expense (benefit)	$ 11,900,000
Tax Cuts and Jobs Act of 2017, income tax expense (benefit), remeasurement of certain deferred tax assets and liabilities	8,900,000
Tax Cuts and Jobs Act of 2017, income tax expense (benefit), transition tax fior accumulated foreign earnings	3,000,000
Operating loss carryforwards	1,000,000	$ 8,900,000
Valuation allowance	800,000	0
Income tax penalties and interest accrued	0	0	$ 0
Unrecognized tax benefits that would impact effective tax rate	2,000,000
Federal | Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward		1,000,000
State and Local Jurisdiction | Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	10,100,000	$ 10,000,000
Evolution Robotics, Inc. (ER) | State and Local Jurisdiction | Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 1,000,000

Industry Segment, Geographic 74

Industry Segment, Geographic Information and Significant Customers (Details Textual) - segment	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments	1
Geographic Concentration Risk | Revenue | Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage		48.80%	51.20%	56.00%
Customer Concentration Risk | Revenue | 1 Customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage		13.50%	10.40%
Customer Concentration Risk | Revenue | Sales On Demand Corporation (SODC)
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage			12.90%	13.30%
Customer Concentration Risk | Revenue | Robopolis SAS
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage			12.30%	12.70%
Customer Concentration Risk | Consumer Robot Revenue | 15 Customers
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage		62.70%	72.80%	76.60%

Quarterly Information (Unaudi75

Quarterly Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Details of Quarterly Information (Unaudited)
Revenue	$ 326,897	$ 205,399	$ 183,148	$ 168,467	$ 212,494	$ 168,610	$ 148,696	$ 130,804	$ 883,911	$ 660,604	$ 616,778
Gross margin	153,542	102,383	89,891	87,343	106,642	81,060	69,652	61,961	433,159	319,315	288,926
Net income	$ 4,620	$ 22,082	$ 7,903	$ 16,359	$ 13,681	$ 19,512	$ 4,814	$ 3,932	$ 50,964	$ 41,939	$ 44,130
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.76	$ 0.27	$ 0.58	$ 0.49	$ 0.70	$ 0.17	$ 0.13	$ 1.77	$ 1.48	$ 1.47