CarParts.com (PRTS) 10-K 7 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Mar. 02, 2017	Jul. 02, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	U.S. Auto Parts Network, Inc.
Entity Central Index Key	1,378,950
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	PRTS
Amendment Flag	false
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		34,556,623
Entity Public Float			$ 63.5

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Current assets:
Cash and cash equivalents	$ 6,643	$ 5,537
Short-term investments	30	65
Accounts receivable, net of allowances of $36 and $17 at December 31, 2016 and January 2, 2016, respectively	3,266	3,236
Inventory	50,904	51,216
Other current assets	2,815	2,475
Total current assets	63,658	62,529
Property and equipment, net	16,478	18,431
Intangible assets, net	969	1,476
Other non-current assets	1,029	1,320
Total assets	82,134	83,756
Current liabilities:
Accounts payable	33,697	25,523
Accrued expenses	6,860	7,267
Revolving loan payable	0	11,759
Current portion of capital leases payable	542	521
Customer deposits	3,718	2,578
Other current liabilities	1,972	1,276
Total current liabilities	46,789	48,924
Capital leases payable, net of current portion	9,770	10,168
Deferred income taxes	156	944
Other non-current liabilities	2,097	1,577
Total liabilities	58,812	61,613
Commitments and contingencies
Stockholders’ equity:
Series A convertible preferred stock, $0.001 par value; $1.45 per share liquidation value or aggregate of $6,017; 4,150 shares authorized; 4,150 and 4,150 shares issued and outstanding at December 31, 2016 and January 2, 2016, respectively	4	4
Common stock, $0.001 par value; 100,000 shares authorized; 35,068 and 34,137 shares issued and outstanding at December 31, 2016 and January 2, 2016, respectively (445 of which are treasury stock)	35	34
Treasury stock	(1,376)	0
Additional paid-in-capital	180,153	176,873
Accumulated other comprehensive income	557	440
Accumulated deficit	(156,520)	(157,011)
Total stockholders’ equity	22,853	20,340
Noncontrolling interest	469	1,803
Total equity	23,322	22,143
Total liabilities and equity	$ 82,134	$ 83,756

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Accounts receivable, allowances	$ 36	$ 17
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	35,068,000	34,137,000
Common stock, shares outstanding (in shares)	35,068,000	34,137,000
Treasury stock (in shares)	445,000
Series A Convertible Preferred Stock
Series A convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Share liquidation value (in dollars per share)	$ 1.45	$ 1.45
Share aggregate value	$ 6,017	$ 6,017
Series A convertible preferred stock, shares authorized (in shares)	4,150,000	4,150,000
Series A convertible preferred stock, shares issued (in shares)	4,150,000	4,150,000
Series A convertible preferred stock, shares outstanding (in shares)	4,150,000	4,150,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Income Statement [Abstract]
Net sales		$ 303,571	$ 291,091	$ 283,508
Cost of sales	[1]	211,289	207,657	205,058
Gross profit		92,282	83,434	78,450
Operating expenses:
Marketing		43,555	43,279	42,008
General and administrative		17,907	16,509	16,701
Fulfillment		22,975	20,237	20,368
Technology		5,843	5,000	4,863
Amortization of intangible assets		482	464	422
Impairment loss on intangible assets		1,130	0	0
Total operating expenses		91,892	85,489	84,362
Income (loss) from operations		390	(2,055)	(5,912)
Other income (expense):
Other income, net		46	36	65
Interest expense		(1,238)	(1,216)	(1,101)
Total other expense, net		(1,192)	(1,180)	(1,036)
Loss before income taxes		(802)	(3,235)	(6,948)
Income tax (benefit) provision		(199)	(811)	138
Net loss including noncontrolling interests		(603)	(2,424)	(7,086)
Net loss attributable to noncontrolling interests		(1,334)	(1,143)	(207)
Net income (loss) attributable to U.S. Auto Parts		731	(1,281)	(6,879)
Other comprehensive income attributable to U.S. Auto Parts, net of tax:
Foreign currency translation adjustments		9	36	20
Actuarial gain (loss) on defined benefit plan		110	44	(106)
Unrealized loss on investments		(2)	0	0
Total other comprehensive income (loss) attributable to U.S. Auto Parts		117	80	(86)
Comprehensive income (loss) attributable to U.S. Auto Parts		$ 848	$ (1,201)	$ (6,965)
Basic net income (loss) per share (in dollars per share)		$ 0.01	$ (0.04)	$ (0.21)
Diluted net income (loss) per share (in dollars per share)		$ 0.01	$ (0.04)	$ (0.21)
Shares used in computation of basic net income (loss) per share (in shares)		34,765	33,946	33,489
Shares used in computation of diluted net income (loss) per share (in shares)		36,207	33,946	33,489
[1]	Excludes depreciation and amortization expense which is included in marketing, general and administrative and fulfillment expense as described in “Note 1 – Summary of Significant Accounting Policies and Nature of Operations”

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in- Capital	Treasury Stock	Preferred Stock Dividend Distributable	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total Stockholders’ Equity	Noncontrolling Interest
Beginning balance (in shares) at Dec. 28, 2013		4,150	33,352
Beginning balance at Dec. 28, 2013	$ 20,866	$ 4	$ 33	$ 168,693	$ 0	$ 60	$ 446	$ (148,370)	$ 20,866	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares of Auto MD common stock	5,665			2,512					2,512	3,153
Net (loss) income	(6,879)
Net income (loss)	(7,086)							(6,879)	(6,879)	(207)
Issuance of common stock in connection with preferred stock dividends (in shares)			107
Issuance of common stock in connection with preferred stock dividends	0			300		(300)			0
Issuance of shares in connection with stock option exercises (in shares)			144
Issuance of shares in connection with stock option exercises	295			295					295
Issuance of shares in connection with restricted stock units vesting (in shares)			21
Share-based compensation	2,569			2,569					2,569
Common stock dividend distributable on Series A Preferred Stock	0					240		(240)	0
Actuarial loss on defined benefit plan	(106)						(106)		(106)
Unrealized (loss) gain on investments, net of tax	0
Effect of changes in foreign currencies	20						20		20
Ending balance (in shares) at Jan. 03, 2015		4,150	33,624
Ending balance at Jan. 03, 2015	22,223	$ 4	$ 33	174,369	0	0	360	(155,489)	19,277	2,946
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(1,281)
Net income (loss)	$ (2,424)							(1,281)	(1,281)	(1,143)
Issuance of common stock in connection with preferred stock dividends (in shares)			103
Issuance of common stock in connection with preferred stock dividends				241		(241)
Issuance of shares in connection with stock option exercises (in shares)	301		301
Issuance of shares in connection with stock option exercises	$ 135			135					135
Issuance of shares in connection with restricted stock units vesting (in shares)			397
Issuance of shares in connection with restricted stock units vesting	(809)			(809)					(809)
Minimum tax withholding on RSU's (in shares)			(151)
Minimum tax withholding on RSU's	451		$ 1	450					451
Minimum tax withholding on Options (in shares)			(139)
Minimum tax withholdings on Options exercised	(80)			(80)					(80)
Share-based compensation	2,565			2,565					2,565
Issuance of shares in connection with BOD Fees (in shares)			2
Issuance of shares in connection with BOD Fees	2			2					2
Common stock dividend distributable on Series A Preferred Stock						241		(241)
Actuarial loss on defined benefit plan	44						44		44
Unrealized (loss) gain on investments, net of tax	0
Effect of changes in foreign currencies	36						36		36
Ending balance (in shares) at Jan. 02, 2016		4,150	34,137
Ending balance at Jan. 02, 2016	22,143	$ 4	$ 34	176,873	0	0	440	(157,011)	20,340	1,803
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	731							731
Net income (loss)	$ (603)							731	731	(1,334)
Issuance of common stock in connection with preferred stock dividends (in shares)			37
Issuance of common stock in connection with preferred stock dividends				120		(120)
Issuance of shares in connection with stock option exercises (in shares)	442		442
Issuance of shares in connection with stock option exercises	$ 908			908					908
Issuance of shares in connection with restricted stock units vesting (in shares)			774
Issuance of shares in connection with restricted stock units vesting	(1,896)		$ 1	(1,897)					(1,896)
Minimum tax withholding on RSU's (in shares)			(335)
Minimum tax withholding on RSU's	927			927					927
Share-based compensation	3,213			3,213					3,213
Cash Dividend on preferred stock	(120)							(120)	(120)
Issuance of shares in connection with BOD Fees (in shares)			3
Issuance of shares in connection with BOD Fees	9			9					9
Issuance of stock awards (in shares)			10
Treasury Stock	(1,376)				(1,376)				(1,376)
Common stock dividend distributable on Series A Preferred Stock	0					120		(120)
Actuarial loss on defined benefit plan	110						110		110
Unrealized (loss) gain on investments, net of tax	(2)						(2)		(2)
Effect of changes in foreign currencies	9						9		9
Ending balance (in shares) at Dec. 31, 2016		4,150	35,068
Ending balance at Dec. 31, 2016	$ 23,322	$ 4	$ 35	$ 180,153	$ (1,376)	$ 0	$ 557	$ (156,520)	$ 22,853	$ 469

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)	Jan. 02, 2016USD ($)	Jan. 03, 2015USD ($)
Operating activities
Net loss including noncontrolling interests	$ (603)	$ (2,424)	$ (7,086)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization expense	7,510	7,510	8,923
Amortization of intangible assets	482	464	422
Deferred income taxes	(838)	(906)	74
Share-based compensation expense	3,131	2,419	2,371
Stock awards issued for non-employee director service	9	2	0
Impairment loss on intangible assets	1,130	0	0
Amortization of deferred financing costs	70	82	81
Gain from disposition of assets	0	(13)	(96)
Changes in operating assets and liabilities:
Accounts receivable	(30)	568	1,105
Inventory	312	(2,854)	(11,412)
Other current assets	(255)	262	471
Other non-current assets	203	225	(39)
Accounts payable and accrued expenses	7,906	119	6,992
Other current liabilities	1,775	475	(302)
Other non-current liabilities	769	(184)	(261)
Net cash provided by operating activities	21,571	5,745	1,243
Investing activities
Additions to property and equipment	(6,353)	(7,780)	(5,556)
Proceeds from sale of property and equipment	0	13	27
Cash paid for intangibles	(125)	(25)	(200)
Proceeds from sale of marketable securities and investments	1	0	745
Purchases of marketable securities and investments	0	0	(746)
Net cash used in investing activities	(6,477)	(7,792)	(5,730)
Financing activities
Proceeds from revolving loan payable	13,727	15,637	19,506
Payments made on revolving loan payable	(25,485)	(14,900)	(15,258)
Proceeds from sale of equity in subsidiary	0	0	7,000
Payments on capital leases	(587)	(438)	(232)
Treasury stock purchases	(1,387)	0	0
Statutory tax withholding payment for share-based compensation	(969)	(438)	0
Proceeds from exercise of stock options	908	134	295
Payment of liabilities related to financing activities	(100)	(100)	0
Preferred stock dividends paid	(61)	0	0
Net cash (used in) provided by financing activities	(13,954)	(105)	11,311
Effect of exchange rate changes on cash	(34)	36	11
Net change in cash and cash equivalents	1,106	(2,116)	6,835
Cash and cash equivalents, beginning of period	5,537	7,653	818
Cash and cash equivalents, end of period	6,643	5,537	7,653
Supplemental disclosure of non-cash investing and financing activities:
Accrued asset purchases	744	708	1,232
Accrued asset purchases	0	125	0
Property acquired under capital lease	211	1,588	0
Preferred stock dividends declared and not paid	60	0	0
Unrealized loss on investments	(2)	0	0
Supplemental disclosure of cash flow information:
Cash paid during the period for income taxes	89	104	60
Cash paid during the period for interest	$ 1,077	$ 1,145	$ 1,029

Summary of Significant Accounti

Summary of Significant Accounting Policies and Nature of Operations	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Nature of Operations	Summary of Significant Accounting Policies and Nature of Operations U.S. Auto Parts Network, Inc. (including its subsidiaries) is a leading online provider of aftermarket auto parts and accessories and was established in 1995. The Company entered the e-commerce sector by launching its first website in 2000 and currently derives the majority of its revenues from online sales channels. The Company sells its products to individual consumers through a network of websites and online marketplaces. Through AutoMD.com, the Company educates consumers on maintenance and service of their vehicles. The site provides auto information, with tools for diagnosing car troubles, locating repair shops and do-it-yourself (“DIY”) repair guides. Our flagship websites are located at www.autopartswarehouse.com , www.carparts.com , www.jcwhitney.com and www.AutoMD.com and our corporate website is located at www.usautoparts.net . References to the “Company,” “we,” “us,” or “our” refer to U.S. Auto Parts Network, Inc. and its consolidated subsidiaries. The Company’s products consist of collision parts serving the body repair market, engine parts to serve the replacement parts market, and performance parts and accessories. The collision parts category is primarily comprised of body parts for the exterior of an automobile. Our parts in this category are typically replacement parts for original body parts that have been damaged as a result of a collision or through general wear and tear. The majority of these products are sold through our websites. In addition, we sell an extensive line of mirror products, including our own private-label brand called Kool-Vue™, which are marketed and sold as aftermarket replacement parts and as upgrades to existing parts. The engine parts category is comprised of engine components and other mechanical and electrical parts. These parts serve as replacement parts for existing engine parts and are generally used by professionals and do-it-yourselfers for engine and mechanical maintenance and repair. We offer performance versions of many parts sold in each of the above categories. Performance parts and accessories generally consist of parts that enhance the performance of the automobile, upgrade existing functionality of a specific part or improve the physical appearance or comfort of the automobile. The Company is a Delaware C corporation and is headquartered in Carson, California. The Company has employees located in both the United States and the Philippines. Fiscal Year The Company’s fiscal year is based on a 52/53 week fiscal year ending on the Saturday closest to December 31. The fiscal years ended December 31, 2016 (fiscal year 2016 ) and January 2, 2016 (fiscal year 2015 ) are both 52 week periods. The fiscal year ended January 3, 2015 (fiscal year 2014 ) is a 53 week period. Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and its subsidiaries in which it has a controlling interest. On October 8, 2014, AutoMD, Inc. ("AutoMD") sold seven million shares of its common stock to third-party investors, reducing the Company’s ownership interest in AutoMD to 64.1% . In October 2016, the Company purchased an additional two million shares of AutoMD common stock pursuant to its funding milestone obligations under the common stock purchase agreement, increasing the Company's ownership interest in AutoMD to 67.4% . On January 26, 2017, AutoMD entered into redemption agreements with certain third-party investors to redeem an aggregate of five million shares of AutoMD common stock for a purchase price of $1,292 . The redemption agreements increased the Company's ownership interest in AutoMD to 87.9% of AutoMD's outstanding common stock. The remaining 12.1% of AutoMD controlled by third-party investors was repurchased on March 6, 2017. The Company reports noncontrolling interests in consolidated entities as a component of equity separate from the Company’s equity. All inter-company transactions between and among the Company and its consolidated subsidiaries have been eliminated in consolidation. Basis of Presentation During fiscal year 2016 , the Company’s revenues increased 4.3% from fiscal 2015 after having increased in fiscal year 2015 by 2.7% from fiscal year 2014 . In fiscal year 2016 , the Company generated net income of $731 , after incurring net losses of $1,281 and $6,879 in fiscal years 2015 and 2014 , respectively. Based on our current operating plan, we believe that our existing cash, cash equivalents, short-term investments, cash flows from operations and available debt financing will be sufficient to finance our operational cash needs through at least the next twelve months. Should the Company’s operating results not meet expectations in 2017 , it could negatively impact our liquidity as we may not be able to provide positive cash flows from operations in order to meet our working capital requirements. We may need to borrow additional funds from our credit facility, which under certain circumstances may not be available, sell assets or seek additional equity or additional debt financing in the future. There can be no assurance that we would be able to raise such additional financing or engage in such additional asset sales on acceptable terms, or at all. If revenues were to decline and we incur net losses because our strategies to return to consistent profitability are not successful or otherwise, and if we are not able to raise adequate additional financing or proceeds from asset sales to continue to fund our ongoing operations, we will need to defer, reduce or eliminate significant planned expenditures, restructure or significantly curtail our operations. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates made by management include, but are not limited to, those related to revenue recognition, uncollectible receivables, the valuation of short-term investments, valuation of inventory, valuation of deferred tax assets and liabilities, valuation of intangible and other long-lived assets, recoverability of software development costs, contingencies and share-based compensation expense that results from estimated grant date fair values and vesting of issued equity awards. Actual results could differ from these estimates. Statement of Cash Flows The net change in the Company’s book overdraft is presented as an operating activity in the consolidated statement of cash flows. The book overdraft represents a credit balance in the Company’s general ledger but the Company has a positive bank account balance. Cash and Cash Equivalents The Company considers all money market funds and short-term investments purchased with original maturities of ninety days or less to be cash equivalents. Fair Value of Financial Instruments Financial instruments that are not measured at fair value include accounts receivable, accounts payable and debt. Refer to “ Note 3 – Fair Value Measurements ” for additional fair value information. If the Company’s revolving loan payable (see “Note 6 – Borrowings” ) had been measured at fair value, it would be categorized in Level 2 of the fair value hierarchy, as the estimated value would be based on the quoted market prices for the same or similar issues or on the current rates available to the Company for debt of the same or similar terms. The carrying values of cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their short-term maturities. Short-term investments are carried at fair value. Based on the borrowing rates currently available to the Company for bank loans with similar terms and average maturities, the fair value of our revolving loan payable, classified as current liability in our consolidated balance sheet, approximates its carrying amount because the interest rate is variable. Accounts Receivable and Concentration of Credit Risk Accounts receivable are stated net of allowance for doubtful accounts. The allowance for doubtful accounts is determined primarily on the basis of past collection experience and general economic conditions. The Company determines terms and conditions for its customers primarily based on the volume purchased by the customer, customer creditworthiness and past transaction history. Concentrations of credit risk are limited to the customer base to which the Company’s products are sold. The Company does not believe significant concentrations of credit risk exist. Investments Short-term investments are comprised of closed-end funds primarily invested in mutual funds that hold government bonds and stock and short-term money market funds. Mutual funds are classified as short-term investments available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined. All of the Company’s marketable securities and investments are subject to a periodic impairment review. The Company recognizes an impairment charge when a decline in the fair value of its investments below the cost basis is judged to be other-than-temporary. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time and extent to which the fair value has been less than the Company’s cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value. No other-than-temporary impairment charges were recorded on any investments during fiscal years presented. Inventory Inventories consist of finished goods available-for-sale and are stated at the lower of cost or market value, determined using the first-in first-out (“FIFO”) method. The Company purchases inventory from suppliers both domestically and internationally, and routinely enters into supply agreements with Asia-Pacific based suppliers of private label products and U.S.–based suppliers who are primarily drop-ship vendors. The Company believes that its products are generally available from more than one supplier and seeks to maintain multiple sources for its products, both internationally and domestically. The Company primarily purchases products in bulk quantities to take advantage of quantity discounts and to ensure inventory availability. Inventory is reported at the lower of cost or market, adjusted for slow moving, obsolete or scrap product. Inventory at December 31, 2016 and January 2, 2016 included items in-transit to our warehouses, in the amount of $9,767 and $12,241 , respectively. Website and Software Development Costs The Company capitalizes certain costs associated with website and software developed for internal use according to ASC 350-50 - Intangibles – Goodwill and Other – Website Development Costs and ASC 350-40 Intangibles – Goodwill and Other – Internal-Use Software , when both the preliminary project design and testing stage are completed and management has authorized further funding for the project, which it deems probable of completion and to be used for the function intended. Capitalized costs include amounts directly related to website and software development such as payroll and payroll-related costs for employees who are directly associated with, and who devote time to, the internal-use software project. Capitalization of such costs ceases when the project is substantially complete and ready for its intended use. These amounts are amortized on a straight-line basis over two to three years once the software is placed into service. The Company capitalized website and software development costs of $4,977 and $5,664 during fiscal year 2016 and 2015 , respectively. At December 31, 2016 and January 2, 2016 , our internally developed website and software costs amounted to $22,366 and $22,745 , respectively, and the related accumulated amortization and impairment amounted to $18,520 and $17,669 , respectively. Long-Lived Assets and Intangibles Subject to Amortization The Company accounts for the impairment and disposition of long-lived assets, including intangibles subject to amortization, in accordance with ASC - 360 Property, Plant and Equipment (“ASC 360”) . Management assesses potential impairments whenever events or changes in circumstances indicate that the carrying value of an asset or asset group may not be recoverable. An impairment loss will result when the carrying value exceeds the undiscounted cash flows estimated to result from the use and eventual disposition of the asset or asset group. Impairment losses will be recognized in operating results to the extent that the carrying value exceeds the discounted future cash flows estimated to result from the use and eventual disposition of the asset or asset group. The Company continually uses judgment when applying these impairment rules to determine the timing of the impairment tests, undiscounted cash flows used to assess impairments, and the fair value of a potentially impaired asset or asset group. The reasonableness of our judgments could significantly affect the carrying value of our long-lived assets. During the fourth quarter of 2016 , the Company recognized an impairment loss on intangible assets of $1,130 related to the impairment of AutoMD software. As of January 2, 2016 and January 3, 2015 , the Company’s long-lived assets did not indicate a potential impairment under the provisions of ASC 360, therefore no impairment charges were recorded for either fiscal 2015 of fiscal 2014 . Deferred Catalog Expenses Deferred catalog expenses consist of third-party direct costs including primarily creative design, paper, printing, postage and mailing costs for all Company direct response catalogs. Such costs are capitalized as deferred catalog expenses and are amortized over their expected future benefit period. Each catalog is fully amortized within nine months . Deferred catalog expenses are included in other current assets and amounted to $160 and $256 at December 31, 2016 and January 2, 2016 , respectively. Deferred Financing Costs Deferred financing costs are being amortized over the life of the loan using the straight-line method as it is not significantly different from the effective interest method. Revenue Recognition The Company recognizes revenue from product sales and shipping revenues, net of promotional discounts and return allowances, when the following revenue recognition criteria are met: persuasive evidence of an arrangement exists, both title and risk of loss or damage have transferred, delivery has occurred, the selling price is fixed or determinable, and collectability is reasonably assured. The Company retains the risk of loss or damage during transit, therefore, revenue from product sales is recognized at the delivery date to customers. Return allowances, which reduce product revenue by the Company’s best estimate of expected product returns, are estimated using historical experience. Revenue from sales of advertising is recorded when performance requirements of the related advertising program agreement are met. For each of the fiscal years ended 2016 , 2015 and 2014 , the advertising revenue represented approximately 1% , of our total revenue. The Company evaluates the criteria of ASC 605-45 - Revenue Recognition Principal Agent Considerations in determining whether it is appropriate to record the gross amount of product sales and related costs or the net amount earned as commissions. Generally, when the Company is the primary party obligated in a transaction, the Company is subject to inventory risk, has latitude in establishing prices and selecting suppliers, or has several but not all of these indicators, revenue is recorded at gross. Payments received prior to the delivery of goods to customers are recorded as deferred revenue. The Company periodically provides incentive offers to its customers to encourage purchases. Such offers include current discount offers, such as percentage discounts off current purchases and other similar offers. Current discount offers, when accepted by the Company’s customers, are treated as a reduction to the purchase price of the related transaction. Sales discounts are recorded in the period in which the related sale is recognized. Sales return allowances are estimated based on historical amounts and are recorded upon recognizing the related sales. Credits are issued to customers for returned products. Credits for returned products amounted to $23,876 , $23,543 , and $24,903 for fiscal year 2016 , 2015 and 2014 , respectively. No customer accounted for more than 10% of the Company’s net sales. The following table provides an analysis of the allowance for sales returns and the allowance for doubtful accounts (in thousands): Balance at Beginning of Period Charged to Revenue, Cost or Expenses Deductions Balance at End of Period Fifty-Two Weeks Ended December 31, 2016 Allowance for sales returns $ 1,009 $ 23,804 $ (23,876 ) $ 937 Allowance for doubtful accounts 17 254 (235 ) 36 Fifty-Two Weeks Ended January 2, 2016 Allowance for sales returns $ 897 $ 23,655 $ (23,543 ) $ 1,009 Allowance for doubtful accounts 41 29 (53 ) 17 Fifty-Three Weeks Ended January 3, 2015 Allowance for sales returns $ 893 $ 24,907 $ (24,903 ) $ 897 Allowance for doubtful accounts 213 64 (236 ) 41 Cost of Sales Cost of sales consists of the direct costs associated with procuring parts from suppliers and delivering products to customers. These costs include direct product costs, outbound freight and shipping costs, warehouse supplies and warranty costs, partially offset by purchase discounts and cooperative advertising. Total freight and shipping expense included in cost of sales for fiscal year 2016 , 2015 and 2014 was $41,937 , $41,250 , and $40,428 , respectively. Depreciation and amortization expenses are excluded from cost of sales and included in marketing, general and administrative and fulfillment expenses. Warranty Costs The Company or the vendors supplying its products provide the Company’s customers limited warranties on certain products that range from 30 days to lifetime. Historically, the Company’s vendors have been the party primarily responsible for warranty claims. Standard product warranties sold separately by the Company are recorded as deferred revenue and recognized ratably over the life of the warranty, ranging from one to five years . The Company also offers extended warranties that are imbedded in the price of selected private label products sold. The product brands that include the extended warranty coverage are offered at three different service levels: (a) a five year unlimited product replacement, (b) a five year one-time product replacement, and (c) a three year one-time product replacement. Warranty costs relating to merchandise sold under warranty not covered by vendors are estimated and recorded as warranty obligations at the time of sale based on each product’s historical return rate and historical warranty cost. The standard and extended warranty obligations are recorded as warranty liabilities and included in other current liabilities in the consolidated balance sheets. For the fiscal year 2016 and 2015 , the activity in the aggregate warranty liabilities was as follows (in thousands): December 31, 2016 January 2, 2016 Warranty liabilities, beginning of period $ 110 $ 218 Adjustments to preexisting warranty liabilities — (109 ) Additions to warranty liabilities 918 53 Reductions to warranty liabilities (139 ) (52 ) Warranty liabilities, end of period $ 889 $ 110 Marketing Expense Marketing costs, including advertising, are expensed as incurred. The majority of advertising expense is paid to internet search engine service providers and internet commerce facilitators. For fiscal year 2016 , 2015 and 2014 , the Company recognized advertising costs of $22,616 , $20,251 and $18,485 , respectively. Marketing costs also include depreciation and amortization expense and share-based compensation expense. General and Administrative Expense General and administrative expense consists primarily of administrative payroll and related expenses, merchant processing fees, legal and professional fees and other administrative costs. General and administrative expense also includes depreciation and amortization expense and share-based compensation expense. Fulfillment Expense Fulfillment expense consists primarily of payroll and related costs associated with warehouse employees and the Company’s purchasing group, facilities rent, building maintenance, depreciation and other costs associated with inventory management and wholesale operations. Fulfillment expense also includes share-based compensation expense. Technology Expense Technology expense consists primarily of payroll and related expenses of our information technology personnel, the cost of hosting the Company’s servers, communications expenses and Internet connectivity costs, computer support and software development amortization expense. Technology expense also includes share-based compensation expense. Share-Based Compensation The Company accounts for share-based compensation in accordance with ASC 718 - Compensation – Stock Compensation (“ASC 718”). All share-based payment awards issued to employees are recognized as share-based compensation expense in the financial statements based on their respective grant date fair values, and are recognized within the statement of comprehensive income or loss as marketing, general and administrative, fulfillment or technology expense, based on employee departmental classifications. Under this standard, compensation expense for both time-based and performance-based restricted stock units is based on the closing stock price of our common shares on the date of grant, and is recognized on a straight-line basis over the requisite service period. Compensation expense for performance-based awards is measured based on the amount of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. Compensation expense for stock options is based on the fair value estimated on the date of grant using an option pricing model, and is recognized over the vesting period of three to four years. The Company currently uses the Black-Scholes option pricing model to estimate the fair value of share-based payment awards for such stock options, which is affected by the Company’s stock price and a number of assumptions, including expected volatility, expected life, risk-free interest rate and expected dividends. The Company incorporates its own historical volatility into the grant-date fair value calculations for the stock options. The expected term of an award is based on combining historical exercise data with expected weighted time outstanding. Expected weighted time outstanding is calculated by assuming the settlement of outstanding awards is at the midpoint between the remaining weighted average vesting date and the expiration date. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected life of awards. The dividend yield assumption is based on the Company’s expectation of paying no dividends on its common stock. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures significantly differ from those estimates. The Company considers many factors when estimating expected forfeitures, including employee class, economic environment, and historical experience. The Company accounts for equity instruments issued in exchange for the receipt of services from non-employee directors in accordance with the provisions of ASC 718. The Company accounts for equity instruments issued in exchange for the receipt of goods or services from other than employees in accordance with ASC 505-50 - Equity-Based Payments to Non-Employees . Costs are measured at the estimated fair market value of the consideration received or the estimated fair value of the equity instruments issued, whichever is more reliably measurable. The value of equity instruments issued for consideration other than employee services is determined on the earlier of a performance commitment or completion of performance by the provider of goods or services. Equity instruments awarded to non-employees are periodically re-measured as the underlying awards vest unless the instruments are fully vested, immediately exercisable and non-forfeitable on the date of grant. The Company accounts for modifications to its share-based payment awards in accordance with the provisions of ASC 718. Incremental compensation cost is measured as the excess, if any, of the fair value of the modified award over the fair value of the original award immediately before its terms are modified, measured based on the share price and other pertinent factors at that date, and is recognized as compensation cost on the date of modification (for vested awards) or over the remaining service (vesting) period (for unvested awards). Any unrecognized compensation cost remaining from the original award is recognized over the vesting period of the modified award. Other Income, net Other income, net consists of miscellaneous income or expense such as gains/losses from disposition of assets, and interest income comprised primarily of interest income on investments. Interest Expense Interest expense consists primarily of interest expense on our outstanding loan balance, deferred financing cost amortization, and capital lease interest. Income Taxes The Company accounts for income taxes in accordance with ASC 740 - Income Taxes (“ASC 740”). Under ASC 740, deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. When appropriate, a valuation allowance is established to reduce deferred tax assets, which include tax credits and loss carry forwards, to the amount that is more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences and carryforwards, taxable income in prior carryback years, tax planning strategies and recent financial operations. The Company utilizes a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. The Company considers many factors when evaluating and estimating our tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. As of December 31, 2016 , the Company had no material unrecognized tax benefits, interest or penalties related to federal and state income tax matters. The Company’s policy is to record interest and penalties as income tax expense. Taxes Collected from Customers and Remitted to Governmental Authorities We present taxes collected from customers and remitted to governmental authorities on a net basis in accordance with the guidance on ASC 605-45-50-3 - Taxes Collected from Customers and Remitted to Governmental Authorities . Leases The Company analyzes lease agreements for operating versus capital lease treatment in accordance with ASC 840 Leases . Rent expense for leases designated as operating leases is expensed on a straight-line basis over the term of the lease. For capital leases, the present value of future minimum lease payments at the inception of the lease is reflected as a capital lease asset and a capital lease payable in the consolidated balance sheets. Amounts due within one year are classified as current liabilities and the remaining balance as non-current liabilities. Foreign Currency Translation For each of the Company’s foreign subsidiaries, the functional currency is its local currency. Assets and liabilities of foreign operations are translated into U.S. dollars using the current exchange rates, and revenues and expenses are translated into U.S. dollars using average exchange rates. The effects of the foreign currency translation adjustments are included as a component of accumulated other comprehensive income or loss in the Company’s consolidated balance sheets. Comprehensive Income The Company reports comprehensive income or loss in accordance with ASC 220 - Comprehensive Income . Accumulated other comprehensive income or loss, included in the Company’s consolidated balance sheets, includes foreign currency translation adjustments related to the Company’s foreign operations, actuarial gains and losses on the Company's defined benefit plan and unrealized holding gains and losses from available-for-sale marketable securities and investments. The Company presents the components of net income or loss and other comprehensive income or loss in its consolidated statements of comprehensive operations. Segment Data The Company operates in two reportable operating segments. The criteria we use to identify operating segments are primarily the nature of the products we sell or services we provide and the consolidated operating results that are regularly reviewed by our chief operating decision maker to assess performance and make operating decisions. We identified two reportable operating segments, Base USAP, which is the core auto parts business, and AutoMD, an online automotive repair source, in accordance with ASC 280 - Segment Reporting (“ASC 280”) . Recently Adopted Accounting Pronouncements In July 2015, the FASB issued Accounting Standards Update No. 2015-11, “ Simplifying the Measurement of Inventory ,” (“ASU 2015-11”) which requires an entity to measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable cost of completion, disposal, and transportation. The new standard is effective for fiscal years beginning after December 15, 2016, and interim periods within fiscal years beginning after December 15, 2017. The amendments in ASU 2015-11 should be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. This guidance was adopted by us in the fourth quarter of 2016, and it did not have a material impact on our consolidated financial statements. In November 2014, the FASB issued Accounting Standards Update No. 2014-16 " Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity ". The objective of this Update is to eliminate the use of different methods in practice and thereby reduce existing diversity under GAAP in the accounting for hybrid financial instruments issued in the form of a share. The new standard is effective for fiscal years beginning after December 15, 2015. Early adoption is permitted. The Company has adopted ASU 2014-16 and it did not have a material impact on our financial statements. Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2016-09, “ Compensation - Stock Compensation ” (“ASU 2016-09”). The objective of this update is to simplify accounting related to stock compensation. The new standard is effective for fiscal years beginning after December 15, 2016, and interim periods within those annual periods. The Company is evaluating the financial impacts that ASU 2016-09 will have on the consolidated financial statem

Short-term investments

Short-term investments	12 Months Ended
	Dec. 31, 2016
Investments Schedule [Abstract]
Short-term investments	Short-term investments As of December 31, 2016 , the Company held the following short-term investments, recorded at fair value: Amortized Cost Unrealized Fair Value Gains Losses Mutual funds (1) $ 32 $ — $ (2 ) $ 30 As of January 2, 2016 , the Company held the following short-term investments, recorded at fair value: Amortized Cost Unrealized Fair Value Gains Losses Mutual funds (1) $ 65 $ — $ — $ 65 (1) Mutual funds are classified as short-term investments available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined. Proceeds from the sale of available-for-sale securities are disclosed separately in the accompanying consolidated statements of cash flow. For fiscal years 2016 and 2015 , the Company recognized no realized gain or loss of from the sale of mutual funds.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. Provisions of ASC 820 establish 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 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. We measure our financial assets and liabilities at fair value on a recurring basis using the following valuation techniques: (a) Market Approach – uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. (b) Income Approach – uses valuation techniques to convert future estimated cash flows to a single present amount based on current market expectations about those future amounts, using present value techniques. Financial Assets Valued on a Recurring Basis As of December 31, 2016 and January 2, 2016 , the Company held certain assets that are required to be measured at fair value on a recurring basis. These included the Company’s financial instruments, including cash and cash equivalents and short-term investments. The following table represents our fair value hierarchy and the valuation techniques used for financial assets measured at fair value on a recurring basis: December 31, 2016 Total Level 1 Level 2 Level 3 Valuation Techniques Assets: Cash and cash equivalents (1) $ 6,643 $ 6,643 $ — $ — (a) Short-term investments – mutual funds (2) 30 30 — — (a) $ 6,673 $ 6,673 $ — $ — January 2, 2016 Total Level 1 Level 2 Level 3 Valuation Techniques Assets: Cash and cash equivalents (1) $ 5,537 $ 5,537 $ — $ — (a) Short-term investments – mutual funds (2) 65 65 — — (a) $ 5,602 $ 5,602 $ — $ — (1) Cash equivalents consist primarily of money market funds and short-term investments with original maturity dates of three months or less at the date of purchase, for which the Company determines fair value through quoted market prices. (2) Short-term investments consist of mutual funds, classified as available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined. During fiscal year 2016 and 2015 , there were no transfers into or out of Level 1 and Level 2 assets. Non-Financial Assets Valued on a Non-Recurring Basis The Company’s long-lived assets, including intangible assets subject to amortization, are measured at fair value on a non-recurring basis. These assets are measured at cost but are written-down to fair value, if necessary, as a result of impairment. During the fourth quarter of fiscal 2016 the Company identified a triggering event related to AutoMD, which indicated certain AutoMD long-lived assets may not be recoverable. As a result, the Company recorded an impairment loss on AutoMD intangible assets of $1,130 . The fair value measurements are categorized as Level 3 of the fair value hierarchy, as the Company developed its own assumptions and analysis to determine if such assets were impaired.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net The Company’s fixed assets are stated at cost less accumulated depreciation, amortization and impairment. Depreciation and amortization expense are provided for in amounts sufficient to relate the cost of depreciable and amortizable assets to operations over their estimated service lives. Depreciation and amortization expense for fiscal year 2016 , 2015 and 2014 was $7,510 , $7,510 and $8,923 , respectively, which included amortization expense of $475 in each year for capital leased assets. The cost and related accumulated depreciation of assets retired or otherwise disposed of are removed from the accounts and the resultant gain or loss is reflected in earnings. Property and equipment consisted of the following at December 31, 2016 and January 2, 2016 : December 31, 2016 January 2, 2016 Land $ 630 $ 630 Building 8,877 8,877 Machinery and equipment 12,368 12,334 Computer software (purchased and developed) and equipment 26,717 27,083 Vehicles 98 136 Leasehold improvements 1,007 1,474 Furniture and fixtures 1,030 1,039 Construction in process 1,539 1,588 52,266 53,161 Less accumulated depreciation and amortization (35,788 ) (34,730 ) Property and equipment, net $ 16,478 $ 18,431 On April 17, 2013, the Company’s wholly-owned subsidiary, Whitney Automotive Group, Inc. (“WAG”) entered into a sales leaseback for its facility in LaSalle, Illinois, receiving $9,750 pursuant to a purchase and sale agreement dated April 17, 2013 between WAG and STORE Capital Acquisitions, LLC. The Company used the net proceeds of $9,507 from this sale to reduce its revolving loan payable. Simultaneously with the execution of the purchase and sale agreement and the closing of the sale of the property, the Company entered into a lease agreement with STORE Master Funding III, LLC (“STORE”) whereby we leased back the property for our continued use as an office, retail and warehouse facility for storage, sale and distribution of automotive parts, accessories and related items for 20 years, terminating on April 30, 2033 . The related assets represent the amounts included in land and building in the summary above. The Company’s initial base annual rent is $853 for the first year (“Base Rent Amount”), after which the rental amount will increase annually on May 1 by the lesser of 1.5% or 1.25 times the change in the Consumer Price Index as published by the U.S. Department of Labor’s Bureau of Labor Statistics, except that in no event will the adjusted annual rental amount fall below the Base Rent Amount. We were not required to pay any security deposit. Under the terms of the lease, we are required to pay all taxes associated with the lease, pay for any required maintenance on the property, maintain certain levels of insurance and indemnify STORE for losses incurred that are related to our use or occupancy of the property. The lease was accounted for as a capital lease and the $376 excess of the net proceeds over the net carrying amount of the property is amortized in interest expense on a straight-line basis over the lease term of 20 years. As of December 31, 2016 , the gross carrying value, the accumulated depreciation and the net carrying value of all capital leased assets included in property and equipment were $11,306 , $2,273 and $9,033 , respectively. As of January 2, 2016 , the gross carrying value, the accumulated depreciation and the net carrying value of all capital leased assets included in property and equipment were $11,543 , $1,839 and $9,704 , respectively. Construction in process primarily relates to the Company’s internally developed software. Certain of the Company’s net property and equipment were located in the Philippines as of December 31, 2016 and January 2, 2016 , in the amount of $367 and $302 , respectively. Depreciation of property and equipment is provided using the straight-line method for financial reporting purposes, at rates based on the following estimated useful lives: Years Machinery and equipment 2 - 5 Computer software (purchased and developed) 2 - 3 Computer equipment 2 - 5 Vehicles 3 - 5 Leasehold improvements* 3 - 5 Furniture and fixtures 3 - 7 Facility subject to capital lease 20 * The estimated useful life is the lesser of 3 - 5 years or the lease term, whichever is shorter.

Intangible Assets, Net

Intangible Assets, Net	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	Intangible Assets, Net Intangible assets consisted of the following at December 31, 2016 and January 2, 2016 : Useful Life December 31, 2016 January 2, 2016 Gross Carrying Amount Accumulated Amort. and Impairment Net Carrying Amount Gross Carrying Amount Accum. Amort. and Impairment Net Carrying Amount Intangible assets subject to amortization: Product design intellectual property 4 years 2,750 (2,620 ) 130 2,750 (2,361 ) 389 Patent license agreements 3 - 5 years 562 (368 ) 194 562 (219 ) 343 Domain and trade names 10 years 1,407 (762 ) 645 1,407 (663 ) 744 Total $ 4,719 $ (3,750 ) $ 969 $ 4,719 $ (3,243 ) $ 1,476 Intangible assets subject to amortization are amortized on a straight-line basis. Amortization expense relating to intangibles totaled $507 , $464 and $422 for fiscal year 2016 , 2015 and 2014 , respectively. The following table summarizes the future estimated annual amortization expense for these assets over the next five years and thereafter: 2017 $ 319 2018 185 2019 100 2020 100 2021 100 Thereafter 165 Total $ 969

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Borrowings	Borrowings The Company maintains an asset-based revolving credit facility that provides for, among other things a revolving commitment in an aggregate principal amount of up to $30,000 , which is subject to a borrowing base derived from certain receivables, inventory and property and equipment. At December 31, 2016 , our outstanding revolving loan balance was $0 . The customary events of default under the credit facility (discussed below) include certain subjective acceleration clauses, which management has determined the likelihood of such acceleration is more than remote, considering the recurring losses experienced by the Company, therefore a current classification of our revolving loan payable was required. On November 15, 2016, the Company and JPMorgan Chase Bank, N.A. (“JPMorgan”) entered into the Tenth Amendment to Credit Agreement and Third Amendment to Pledge and Security Agreement (the “Amendment”), which amended the Credit Agreement previously entered into by the Company, certain of its domestic subsidiaries and JPMorgan on April 26, 2012 (as amended, the “Credit Agreement”) and the Pledge and Security Agreement previously entered into by the Company, certain of its domestic subsidiaries and JPMorgan on April 26, 2012. Pursuant to the Amendment, letters of credit can be issued if after giving effect to such issuance, the letters of credit exposure shall not exceed $20,000 , which was an increase from the previously agreed upon $15,000 . As of December 31, 2016 , our outstanding letters of credit balance was $11,658 . The following amendments to the Credit Agreement and Security Agreement were also made under the Tenth Amendment: • The aggregate additional principal amount of indebtedness that is permitted related to capital leases was increased from $2,000 to $3,500 . • The Company’s letters of credit exposure was increased from $15,000 to $20,000 . • Under the terms of the Security Agreement, cash receipts are deposited into a lock-box, which are at the Company’s discretion unless the “cash dominion period” is in effect, during which cash receipts will be used to reduce amounts owing under the Credit Agreement. The cash dominion period is triggered in an event of default or if excess availability is less than the $3,600 for three consecutive business days, and will continue until, during the preceding 60 consecutive days, no event of default existed and excess availability has been greater than $3,600 at all times (with the trigger subject to adjustment based on the Company’s revolving commitment). • The Company’s required excess availability related to the “Covenant Testing Trigger Period” (as defined under the Credit Agreement) under the revolving commitment under the Credit Agreement is less than $2,400 for the period commencing on any day that excess availability is less than $2,400 for three consecutive business days, and continuing until excess availability has been greater than or equal to $2,400 at all times for 45 consecutive days (with the trigger subject to adjustment based on the Company’s revolving commitment). • The trigger, requiring the Company to provide certain reports under the Credit Agreement, relating to excess availability under the revolving commitment under the Credit Agreement is less than $3,600 for the period commencing on any day that excess availability is less than $3,600 for three consecutive business days, and continuing until excess availability has been greater than or equal to $3,600 at all times for 45 consecutive days (with the trigger subject to adjustment based on the Company’s revolving commitment). Loans drawn under the credit facility bear interest at a per annum rate equal to either (a) LIBOR plus an applicable margin of 1.25% , or (b) a “base rate” subject to an increase or reduction by up to 0.25% per annum based on the Company's fixed charge coverage ratio. At December 31, 2016 , the Company’s LIBOR based interest rate was 2.06% (on $0 principal) and the Company’s prime based rate was 3.50% (on $0 principal). A commitment fee, based upon undrawn availability under the Credit Facility bearing interest at a rate of 0.25% per annum, is payable monthly. Certain of the Company’s domestic subsidiaries are co-borrowers (together with the Company, the “Borrowers”) under the Credit Agreement, and certain other domestic subsidiaries are guarantors (the “Guarantors” and, together with the Borrowers, the “Loan Parties”) under the Credit Agreement. The Borrowers and the Guarantors are jointly and severally liable for the Borrowers’ obligations under the Credit Agreement. The Loan Parties’ obligations under the Credit Agreement are secured, subject to customary permitted liens and certain exclusions, by a perfected security interest in (a) all tangible and intangible assets and (b) all of the capital stock owned by the Loan Parties (limited, in the case of foreign subsidiaries, to 65% of the capital stock of such foreign subsidiaries). The Borrowers may voluntarily prepay the loans at any time. The Borrowers are required to make mandatory prepayments of the loans (without payment of a premium) with net cash proceeds received upon the occurrence of certain “prepayment events,” which include certain sales or other dispositions of collateral, certain casualty or condemnation events, certain equity issuances or capital contributions, and the incurrence of certain debt. The Credit Agreement contains customary representations and warranties and customary affirmative and negative covenants applicable to the Company and its subsidiaries, including, among other things, restrictions on indebtedness, liens, fundamental changes, investments, dispositions, prepayment of other indebtedness, mergers, and dividends and other distributions. Events of default under the Credit Agreement include: failure to timely make payments due under the Credit Agreement; material misrepresentations or misstatements under the Credit Agreement and other related agreements; failure to comply with covenants under the Credit Agreement and other related agreements; certain defaults in respect of other material indebtedness; insolvency or other related events; certain defaulted judgments; certain ERISA-related events; certain security interests or liens under the loan documents cease to be, or are challenged by the Company or any of its subsidiaries as not being, in full force and effect; any loan document or any material provision of the same ceases to be in full force and effect; and certain criminal indictments or convictions of any Loan Party. As of December 31, 2016 , the Company had capital leases payable of $10,312 . The present value of the net minimum payments on capital leases as of December 31, 2016 is as follows: Total minimum lease payments $ 17,947 Less amount representing interest $ (7,635 ) Present value of net minimum lease payments 10,312 Current portion of capital leases payable (542 ) Capital leases payable, net of current portion $ 9,770

Stockholders' Equity and Share-

Stockholders' Equity and Share-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stockholders' Equity and Share-Based Compensation	Stockholders’ Equity and Share-Based Compensation Non-Controlling Interest Non-controlling interests represent equity interests in consolidated subsidiaries that are not attributable, either directly or indirectly, to the Company (i.e., minority interests). Non-controlling interests include the minority equity holders' proportionate share of the equity of AutoMD. As of March 6, 2017, all of the non-controlling interests of AutoMD were repurchased by the Company. Ownership interests in subsidiaries held by parties other than the Company are presented as non-controlling interests within stockholders' equity, separately from the equity held by the Company. Revenues, expenses, net loss and other comprehensive income are reported in the consolidated financial statements at the consolidated amounts, which includes amounts attributable to both the Company's interest and the non-controlling interests in AutoMD. Net loss and other comprehensive income is then attributed to the Company's interest and the non-controlling interests. Net loss to non-controlling interests is deducted from net loss in the consolidated statements of comprehensive operations to determine net loss attributable to the Company's common stockholders. The table below presents the changes in the Company's ownership interest in AutoMD on the Company's equity as of the dates indicated: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Net income (loss) attributable to U.S. Auto Parts stockholders' $ 731 $ (1,281 ) $ (6,879 ) Transfers (to) from the noncontrolling interest: Increase in U.S. Auto Parts paid-in-capital from sale of AutoMD common stock — — 2,512 Changes from net income (loss) attributable to U.S. Auto Parts stockholders' and transfers to noncontrolling interest $ 731 $ (1,281 ) $ (4,367 ) Common Stock The Company has 100,000 shares of common stock authorized. We have never paid cash dividends on our common stock. The following issuances of common stock were made during the fiscal year ended December 31, 2016 : • The Company issued 442 shares of common stock from option exercises under its various share-based compensation plans. • The Company issued 439 shares of common stock from restricted stock units that vested during the period. • The Company issued 10 shares of common stock for advisory services previously provided by a consultant. • 37 shares of common stock were issued as stock dividends on the Series A Preferred. • The Company issued 3 shares of common stock to one non-employee member of the Board of Directors for service fees earned during the period. Treasury Stock On November 15, 2016, our Board of Directors approved a share repurchase program which authorizes the Company to purchase up to $5,000 of its outstanding shares of common stock. Purchases under the Company’s repurchase program may be made from time to time in the open market, in negotiated transactions off the market, or in such other manner as determined by the Company, including through plans complying with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. The share repurchase program will expire on March 4, 2017, unless extended or shortened by the Board of Directors. As of December 31, 2016, the Company repurchased 445 shares of common stock at an average price of $3.09 , for an aggregate purchase price of approximately $1,376 , net of costs. Series A Convertible Preferred Stock On March 25, 2013, the Company authorized the issuance of 4,150 shares of Series A Preferred and entered into a Securities Purchase Agreement pursuant to which the Company agreed to sell up to an aggregate of 4,150 shares of our Series A Preferred, $0.001 par value per share at a purchase price per share of $1.45 for aggregate proceeds to the Company of approximately $6,017 . On March 25, 2013, we sold 4,000 shares of Series A Preferred for aggregate proceeds of $5,800 . On April 5, 2013, we sold the remaining 150 shares of Series A Preferred for aggregate proceeds of $217 . The Company incurred issuance costs of $847 and used the net proceeds from the sale of the Series A Preferred to reduce its revolving loan payable. Each share of Series A Preferred is convertible into shares of our common stock at the initial conversion rate of one share of common stock for each share of Series A Preferred. The conversion will be adjusted for certain non-price based events, such as dividends and distributions on the common stock, stock splits, combinations, recapitalizations, reclassifications, mergers, or consolidations. If not previously converted by the holder, the Series A Preferred will automatically convert to common stock if the volume weighted average price for the common stock for any 30 consecutive trading days is equal to or exceeds $4.35 per share. The shares that would be issued if the contingently convertible Series A Preferred were converted are not excluded from the calculation of diluted earnings per share for the fiscal year ended December 31, 2016 (refer to “Note 8 – Net Loss Per Share” for anti-dilutive securities). In the event of any liquidation event, which includes changes of control of the Company and sales or other dispositions by the Company of more than 50% of its assets, the Series A Preferred is entitled to receive, prior and in preference to any distribution to the common stock, an amount per share equal to $1.45 per share of Series A Preferred, plus all then accrued but unpaid dividends on such Series A Preferred. Following this distribution, if assets or surplus funds remain, the holders of the common stock shall share ratably in all remaining assets of the Company, based on the number of shares of common stock then outstanding. Notwithstanding the foregoing, if, in connection with any liquidation event, a holder of Series A Preferred would receive an amount greater than $1.45 per share of Series A Preferred by converting such shares held by such holder into shares of common stock, then such holder shall be treated as though such holder had converted such shares of Series A Preferred into shares of common stock immediately prior to such liquidation event, whether or not such holder had elected to so convert. Dividends on the Series A Preferred are payable quarterly at a rate of $0.058 per share per annum in cash, in shares of common stock or in any combination of cash and common stock as determined by the Company’s Board of Directors. Certain conditions are required to be satisfied in order for the Company to pay dividends on the Series A Preferred in shares of common stock, including (i) the common stock being registered pursuant to Section 12(b) or (g) of the Securities Exchange Act of 1934, as amended, (ii) the common stock being issued having been approved for listing on a trading market and (iii) the common stock being issued either being covered by an effective registration statement or being freely tradable without restriction under Rule 144 (subject to certain exceptions). The Series A Preferred shall each be entitled to one vote per share for each share of common stock issuable upon conversion thereof (excluding from any such calculation any dividends accrued on such shares) and shall vote together with the holders of common stock as a single class on any matter on which the holders of common stock are entitled to vote. In addition, the Company must obtain the consent of holders of at least a majority of the then outstanding Series A Preferred in connection with (a) any amendment, alteration or repeal of any provision of the certificate of incorporation or bylaws of the Company as to adversely affect the preferences, rights or voting power of the Series A Preferred, or (b) the creation, authorization or issuance of any additional Series A Preferred or any other class or series of capital stock of the Company ranking senior to or on parity with the Series A Preferred or any security convertible into, or exchangeable or exercisable for Series A Preferred or any other class or series of capital stock of the Company ranking senior to or on parity with the Series A Preferred. Concurrent with the Company’s issuance of Series A Preferred, the Company, certain of its domestic subsidiaries and JPMorgan entered into a Second Amended Credit Agreement to allow the Company to pay cash dividends on the Series A Preferred in an aggregate amount of up to $400 per year and pay cash in lieu of issuing fractional shares upon conversion of or in payment of dividends on the Series A Preferred (refer to “Note 6 – Borrowings” of our Notes to Consolidated Financial Statements for additional details). For the fiscal year ended January 3, 2015, the Company recorded dividends of $240 . The Company issued 83 shares of common stock in payment of the fiscal 2014 dividends. There were no accrued dividends outstanding as of January 3, 2015. For the fiscal year ended January 2, 2016, the Company recorded dividends of $241 . The Company issued 103 shares of common stock in payment of the fiscal 2015 dividends. There were no accrued dividends outstanding as of January 2, 2016. For the fiscal year ended December 31, 2016, the Company recorded dividends of $241 . The Company issued 37 shares of common stock in payment of the fiscal 2016 dividends. There were $61 dividends accrued as of December 31, 2016. Share-Based Compensation Plan Information The Company adopted the 2016 Equity Incentive Plan ("2016 Equity Plan") on March 9, 2016, which became effective on May 31, 2016, following stockholder approval. Subject to adjustment for certain changes in the Company’s capitalization, the aggregate number of shares of the Company’s common stock that may be issued under the 2016 Equity Plan will not exceed the sum of (i) two million five hundred thousand ( 2,500 ) new shares, (ii) the number of unallocated shares remaining available for the grant of new awards under the Company’s prior equity plans described below (the “Prior Equity Plans”) as of the effective date of the 2016 Plan (which was equal to 3,894 shares as of May 31, 2016) and (iii) any shares subject to a stock award under the Prior Equity Plans that are not issued because such stock award expires or otherwise terminates without all of the shares covered by such stock award having been issued, that are not issued because such stock award is settled in cash, that are forfeited back to or repurchased by the Company because of the failure to meet a contingency or condition required for the vesting of such shares, or that are reacquired, withheld (or not issued) to satisfy a tax withholding obligation in connection with an award or to satisfy the purchase price or exercise price of a stock award. In addition, the share reserve will automatically increase on January 1st of each year, for a period of nine years, commencing on January 1, 2017 and ending on (and including) January 1, 2026, in an amount equal to one million five hundred thousand ( 1,500 ) shares per year; however the Board of Directors of the Company may act prior to January 1st of a given year to provide that there will be no January 1st increase in the share reserve for such year or that the increase in the share reserve for such year will be a lesser number of shares of common stock than would otherwise occur pursuant the automatic increase. Options granted under the 2016 Equity Plan generally expire no later than ten years from the date of grant and generally vest over a period of four years. The exercise price of all option grants must be equal to 100% of the fair market value on the date of grant. As of December 31, 2016, 6,307 shares were available for future grants under the 2016 Equity Plan. The Company adopted the 2007 Omnibus Incentive Plan (the “2007 Omnibus Plan”) in January 2007, which became effective on February 8, 2007, the effective date of the registration statement filed in connection with the Company’s initial public offering. Under the 2007 Omnibus Plan, the Company was previously authorized to issue 2,400 shares of common stock, under various instruments to eligible employees and non-employees of the Company, plus an automatic annual increase on the first day of each of the Company’s fiscal years beginning on January 1, 2008 and ending on January 1, 2017 equal to (i) the lesser of (A) 1,500 shares of common stock or (B) five percent (5)% of the number of shares of common stock outstanding on the last day of the immediately preceding fiscal year or (ii) such lesser number of shares of common stock as determined by the Company’s Board of Directors. Options granted under the 2007 Omnibus Plan generally expire no later than ten years from the date of grant and generally vest over a period of four years . The exercise price of all option grants must be equal to 100% of the fair market value on the date of grant. The 2007 Omnibus Plan also allows for the grant of options to purchase common stock and common stock awards to non-employee directors. As of December 31, 2016 , 0 shares were available for future grants under the 2007 Omnibus Plan. The Company adopted the 2007 New Employee Incentive Plan (the “2007 New Employee Plan”) in October 2007. Under the 2007 New Employee Plan, the Company was authorized to issue 2,000 shares of common stock under various instruments solely to new employees. Options granted under the 2007 New Employee Plan generally expire no later than ten years from the date of grant and generally vest over a period of four years . The exercise price of all option grants must not be less than 100% of the fair market value on the date of grant. As of December 31, 2016 , 0 shares were available for future grants under the 2007 New Employee Plan. The Company adopted the U.S. Auto Parts Network, Inc. 2006 Equity Incentive Plan (the “2006 Plan”) in March 2006. All stock options to purchase common stock granted to employees in 2006 were granted under the 2006 Plan and had exercise prices equal to the fair value of the underlying stock, as determined by the Company’s Board of Directors on the applicable option grant date. After fiscal year 2008, no shares have been available for future grants under the 2006 Plan. The following tables summarizes the Company’s stock option activity for the fiscal years ended, and details regarding the options outstanding and exercisable at December 31, 2016 , and January 2, 2016 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate (1) Options outstanding, January 2, 2016 5,841 $ 2.80 Granted 1,000 $ 3.03 Exercised (442 ) $ 2.06 Cancelled: Forfeited (149 ) $ 2.47 Expired (122 ) $ 7.66 Options outstanding, December 31, 2016 6,128 $ 2.81 5.74 $ 6,561 Vested and expected to vest at December 31, 2016 5,658 $ 2.82 5.49 $ 6,111 Options exercisable, December 31, 2016 4,220 $ 2.92 4.49 $ 4,618 Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate (1) Options outstanding, January 3, 2015 5,281 $ 2.85 Granted 1,315 $ 2.24 Exercised (301 ) $ 1.45 Cancelled: Forfeited (256 ) $ 2.06 Expired (198 ) $ 3.31 Options outstanding, January 2, 2016 5,841 $ 2.80 6.03 $ 4,333 Vested and expected to vest at January 2, 2016 5,285 $ 2.88 5.74 $ 3,853 Options exercisable, January 2, 2016 3,735 $ 3.21 4.54 $ 2,479 (1) These amounts represent the difference between the exercise price and the closing price of U.S. Auto Parts Network, Inc. common stock on December 31, 2016 as reported on the NASDAQ Stock Market, for all options outstanding that have an exercise price currently below the closing price. The weighted-average fair value of options granted during fiscal year 2016 , 2015 and 2014 was $1.65 , $1.19 and $1.34 , respectively. The intrinsic value of stock options at the date of the exercise is the difference between the fair value of the stock at the date of exercise and the exercise price. During fiscal year 2016 , 2015 and 2014 , the total intrinsic value of the exercised options was $599 , $346 and $153 , respectively. The Company had $1,344 of unrecognized share-based compensation expense related to stock options outstanding as of December 31, 2016 , which expense is expected to be recognized over a weighted-average period of 2.34 years. The following tables summarize the Company’s stock option activity under the AutoMD 2014 Equity Incentive Plan (the "AMD Plan") for the fiscal years ended, and details regarding the options outstanding and exercisable at December 31, 2016 and January 2, 2016 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Options outstanding, January 2, 2016 1,430 $ 1.00 Granted 10 $ 1.00 Exercised — $ — Cancelled: Forfeited (35 ) $ 1.00 Expired — $ — Options outstanding, December 31, 2016 1,405 $ 1.00 8.20 Vested and expected to vest at December 31, 2016 1,044 $ 1.00 8.19 Options exercisable, December 31, 2016 632 $ 1.00 8.14 Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Options outstanding, January 3, 2015 180 $ 1.00 Granted 1,250 $ 1.00 Exercised — $ — Cancelled: Forfeited — $ — Expired — $ — Options outstanding, January 2, 2016 1,430 $ 1.00 9.19 $ — Vested and expected to vest at January 2, 2016 1,061 $ 1.00 9.19 $ — Options exercisable, January 2, 2016 49 $ 1.00 8.92 $ — At December 31, 2016 520 shares were available for future grants under the AMD Plan. The weighted-average fair value of options granted during fiscal year 2016 , 2015 and 2014 was $0.55 , $0.55 and $0.56 , respectively. The intrinsic value of stock options at the date of the exercise is the difference between the fair value of the stock at the date of exercise and the exercise price. The Company had $224 of unrecognized share-based compensation expense related to stock options outstanding as of December 31, 2016 , which expense is expected to be recognized over a weighted-average period of 2.20 years. Options exercised under all share-based compensation plans are granted net of the minimum statutory withholding requirements that we pay in cash to the appropriate taxing authorities on behalf of our employees. For those employees who elect not to receive shares net of the minimum statutory withholding requirements, the appropriate taxes are paid directly by the employee. During fiscal 2016 , we withheld 0 shares to satisfy $0 of employees' tax obligations and 0 shares related to the net settlement of the stock options. During fiscal 2015 , we withheld 27 shares to satisfy $80 of employees' tax obligations and 112 shares related to the net settlement of the stock options. Restricted Stock Units During 2016 and 2015 the Company granted an aggregate of 954 and 435 RSUs, respectively, to certain employees of the Company. The RSUs were granted under the 2007 Omnibus Plan, and reduced the pool of equity instruments available under that plan. During 2016 there were 382 RSUs granted that were time-based and 572 were performance-based. All of the RSUs granted during 2015 were time-based. As of March 3, 2017, 525 of the performance-based RSUs met the maximum performance criteria upon certification by the Compensation Committee and 47 PSUs were forfeited. Of the RSUs granted during 2015, 348 vested, 30 remain unvested, and 57 were forfeited during 2016. The vesting of each RSU is subject to the employee’s continued employment through applicable vesting dates. Some RSUs granted to certain executives may vest on an accelerated basis in part or in full upon the occurrence of certain events. The RSUs are accounted for as equity awards and are measured at fair value based upon the grant date price of the Company's common stock. The closing price of the Company's common stock on January 21, 2016 and February 29, 2016, the date of each grant was $2.64 and $2.75 , respectively. The closing price of the Company's common stock on January 29, 2015, March 23, 2015, May 20, 2015, June 23, 2015 and July 28, 2015, the date of each grant, was $2.29 , $2.18 , $2.33 , $2.23 , and $2.18 per share, respectively. Compensation expense is recognized on a straight-line basis over the requisite service period of one -to- three years. Compensation expense for performance-based awards is measured based on the amount of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. For the fiscal year ended December 31, 2016 , we recorded compensation expense of $ 1,626 related to RSU's. As of December 31, 2016 , there was unrecognized compensation expense of $ 600 related to unvested RSUs based on awards that are expected to vest. The unrecognized compensation expense is expected to be recognized over a weighted-average period of 0.63 years. Stock Option Exchange Program On July 9, 2013, the Company’s stockholders approved a proposed stock option exchange program for the exchange of certain outstanding stock options held by eligible employees for new options to purchase fewer shares. On August 12, 2013, the Company commenced an offering to eligible employees to voluntarily exchange certain vested and unvested stock options with exercise prices above $4.00 per share at an exchange ratio of 3.5 to 1 to be granted following the expiration of the tender offer with exercise prices equal to the fair market value of one share of the Company’s common stock on the day the new options were issued. Stock options to purchase an aggregate of 3,733 shares with exercise prices ranging from $4.01 to $11.68 were eligible for tender at the commencement of the program. The Company’s non-employee directors were not eligible to participate in the program. The terms and conditions of the new options are subject to an entirely new four year vesting schedule where 25% will vest on the first anniversary, and the remaining 75% will vest monthly over the following 36 months . All new options have a ten year contractual term. The offer period for the stock option exchange ended on September 9, 2013. There were no modifications or exchanges to share based payment awards in fiscal 2015 or 2016 . On September 10, 2013, the Company accepted for exchange 3,475 eligible options to purchase common stock, with a weighted average exercise price of $6.65 for 45 eligible employees, and issued 993 unvested options to purchase shares of the Company’s common stock with an exercise price of $0.9866 , the closing price of the Company’s common stock on that day. Using the Black-Scholes option pricing model, the Company determined that the fair value of the surrendered stock options on a grant-by-grant basis was lower than the fair value of the new stock options, as of the date of the exchange, resulting in incremental fair value of $422 . The incremental fair value as a result of the stock option exchange and the remaining compensation expense associated with the surrendered stock options will be recorded as compensation expense over the four year vesting period of the new options. The fair value of the surrendered stock options and the new stock options was estimated on the date of the exchange using the Black-Scholes option pricing model with the following assumptions: Surrendered Stock Options New Stock Options Expected life 1.93 – 6.87 years 5.84 years Risk-free interest rate 0.5% – 2.4% 2.0% Expected volatility 55% – 73% 72% Expected dividend yield —% —% Warrants On May 5, 2009, the Company issued warrants to purchase up to 30 shares of common stock at an exercise price of $2.14 per share. On April 27, 2010, the Company issued additional warrants to purchase up to 20 shares of common stock at an exercise price of $8.32 per share. Both issuances of warrants terminate seven years after their grant date. The warrants were issued in connection with the financial advisory services provided by a consultant to the Company. On August 8, 2016 10 shares of common stock were issued in settlement of the May 5, 2009 warrants. As of December 31, 2016 , warrants to purchase 20 shares of common stock were outstanding and exercisable. The aggregate intrinsic value of outstanding and exercisable warrants was $0 as of December 31, 2016 , which was calculated as the difference between the exercise price of underlying awards and the closing price of the Company’s common stock for warrants that were in-the-money. No warrants share-based compensation expense was recognized during the fiscal years 2016 , 2015 and 2014 . The Company had no unrecognized share-based compensation expense related to warrants outstanding as of December 31, 2016 . Share-Based Compensation Expense The fair value of each option grant, excluding those options issued from the stock option exchange program as discussed above, was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions for each of the periods ended: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Expected life 5.57 - 5.61 years 5.34 - 5.52 years 5.30 - 5.37 years Risk-free interest rate 1% - 2% 1% - 2% 2% - 2% Expected volatility 60% - 61% 59% - 60% 62% - 68% Expected dividend yield —% —% —% Share-based compensation from options and RSUs, is included in our consolidated statements of comprehensive operations, as follows: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Marketing expense $ 433 $ 518 $ 540 General and administrative expense 2,111 1,614 1,476 Fulfillment expense 450 241 220 Technology expense 137 46 135 Total share-based compensation expense $ 3,131 $ 2,419 $ 2,371 The share-based compensation expense is net of amounts capitalized to internally-developed software of $83 , $146 and $196 during the fiscal year 2016, 2015, and 2014, respectively. No tax benefit was recognized for fiscal years 2016, 2015, and 2014 due to the valuation allowance position. Under ASC 718, forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures significantly differ from those estimates. The Company’s estimated forfeiture rates are calculated based on actual historical forfeitures experienced under our equity plans. The Company's forfeiture rates were 10% - 34% for fiscal years 2016, 2015, and 2014.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share The following table sets forth the computation of basic and diluted net income (loss) per share: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Net income (loss) per share: Numerator: Net income (loss) attributable to U.S. Auto Parts $ 731 $ (1,281 ) $ (6,879 ) Dividends on Series A Convertible Preferred Stock (241 ) (241 ) (240 ) Net income (loss) available to common shares $ 490 $ (1,522 ) $ (7,119 ) Denominator: Weighted-average common shares outstanding (basic) 34,765 33,946 33,489 Common equivalent shares from common stock options, preferred stock and warrants 1,442 — — Weighted-average common shares outstanding (diluted) 36,207 33,946 33,489 Basic net income (loss) per share $ 0.01 $ (0.04 ) $ (0.21 ) Diluted net income (loss) per share $ 0.01 $ (0.04 ) $ (0.21 ) The anti-dilutive securities, which are excluded from the calculation of diluted earnings per share due to the Company’s net loss position for the periods then ended (including securities that would otherwise be excluded from the calculation of diluted earnings per share due the Company’s stock price), are as follows (in thousands): Fiscal Year December 31, 2016 January 2, 2016 January 3, 2015 Common stock warrants 20 50 50 Series A Convertible Preferred Stock 4,150 4,150 4,150 Options to purchase common stock 2,142 5,941 5,467 Restricted Stock Units — 839 796 Total 6,312 10,980 10,463

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of loss before income tax provision consist of the following: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Domestic operations $ (1,305 ) $ (3,718 ) $ (7,424 ) Foreign operations 503 483 476 Total loss before income taxes $ (802 ) $ (3,235 ) $ (6,948 ) Income tax (benefit) provision for fiscal year 2016 , 2015 and 2014 consists of the following: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Current: Federal tax $ — $ — $ — State tax 7 7 (15 ) Foreign tax 162 88 78 Total current taxes 169 95 63 Deferred: Federal tax (331 ) (1,887 ) (2,232 ) State tax (616 ) 591 (125 ) Foreign tax — 61 74 Total deferred taxes (947 ) (1,235 ) (2,283 ) Valuation allowance 579 329 2,358 Income tax (benefit) provision $ (199 ) $ (811 ) $ 138 Income tax (benefit) provision differs from the amount that would result from applying the federal statutory rate as follows: December 31, 2016 January 2, 2016 January 3, 2015 Income tax at U.S. federal statutory rate $ (273 ) $ (1,100 ) $ (2,362 ) Share-based compensation 316 50 33 State income tax, net of federal tax effect (559 ) 672 (143 ) Foreign tax 20 (18 ) 117 Basis difference in subsidiary equity (267 ) (820 ) — Other (15 ) 76 127 Change in valuation allowance 579 329 2,366 Effective tax (benefit) provision $ (199 ) $ (811 ) $ 138 For fiscal year 2016 , 2015 and 2014 , the effective tax rate for the Company was 24.8% , 25.1% and (2.0)% , respectively. The Company’s effective tax rate for fiscal years 2016 and 2015 differs from the U.S. federal rate primarily as a result of the recording of the basis difference in the Company’s subsidiary and the recording of valuation allowances against the Company’s deferred tax assets. The Company’s effective tax rate for fiscal year 2014 differs from the U.S. federal rate primarily as a result of the recording of valuation allowances against the Company’s deferred tax assets. Deferred tax assets and deferred tax liabilities consisted of the following: December 31, 2016 January 2, 2016 Deferred tax assets: Inventory and inventory related allowance $ 839 $ 976 Share-based compensation 5,083 4,924 Amortization 7,636 9,244 Sales and bad debt allowances 749 443 Vacation accrual 224 220 Book over tax amortization — 31 Net operating loss and AMT credit carry-forwards 33,026 30,254 Other 800 843 Total deferred tax assets 48,357 46,935 Valuation Allowance (46,775 ) (46,196 ) Net deferred tax assets 1,582 739 Deferred tax liabilities: Investment in subsidiary — 368 Tax over book depreciation 1,518 639 Foreign tax withholdings — 470 Prepaid catalog expenses 64 100 Total deferred tax liabilities 1,582 1,577 Net deferred tax liabilities $ — $ (838 ) At December 31, 2016 , federal and state net operating loss (“NOL”) carryforwards were $75,261 and $83,027 , respectively. Federal NOL carryforwards of $2,690 were acquired in the acquisition of WAG which are subject to Internal Revenue Code section 382 and limited to an annual usage limitation of $135 . Federal NOL carryforwards begin to expire in 2029 , while state NOL carryforwards begin to expire in 2017 . The state NOL carryforwards expire in the respective tax years as follows: 2017 $ 6,930 2018 1,132 2019 7,646 2020 2,121 2021 4,050 Thereafter 61,148 $ 83,027 On October 8, 2014, AutoMD sold seven million shares of its common stock to third-party investors, reducing the Company’s ownership interest in AutoMD to 64.1% . As a result, AutoMD was excluded from the consolidated state and federal tax filings of the Company for fiscal year 2016. As a result of the investment a deferred tax liability of $ 1,335 was created which reduced the increase in additional paid-in-capital which was created as a result of the investment. At December 31, 2016 , AutoMD had net operating loss carryforwards (NOLs) of approximately $7,506 for federal tax purposes that begin to expire in 2031. AutoMD state NOLs were not material as of December 31, 2016 . Under the provisions of ASC 740, management is required to evaluate whether a valuation allowance should be established against its deferred tax assets based on the consideration of all available evidence using a “more likely than not” standard. Realization of deferred tax assets is dependent upon taxable income in prior carryback years, estimates of future taxable income, tax planning strategies, and reversal of existing taxable temporary differences. ASC 740 provides that forming a conclusion that a valuation allowance is not needed is difficult when there is negative evidence such as cumulative losses in recent years or losses expected in early future years. Based on this evaluation, as of December 31, 2016 , a valuation allowance of $46,775 has been recorded against our deferred tax assets. We are subject to U.S. federal income tax as well as income tax of foreign and state tax jurisdictions. During fiscal 2010, the Company was audited by the Internal Revenue Service for the year ended December 31, 2008. The audit was concluded with no change. The tax years 2012-2015 remain open to examination by the major taxing jurisdictions to which the Company is subject, except the Internal Revenue Service for which the tax years 2013-2015 remain open. The Company does not anticipate a significant change to the amount of unrecognized tax benefits within the next twelve months. Included in accrued expenses are income taxes payable of $35 and $12 for the fiscal year 2016 and 2015 respectively, consisting primarily of current foreign taxes. Included in other non-current liabilities are income taxes payable of $525 , $470 and $409 for the fiscal year 2016, 2015 and 2014 respectively relating to future foreign withholding taxes.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Facilities Leases The Company’s corporate headquarters is located in Carson, California. The Company’s corporate headquarters has a lease term through October 2020, which was renewed in June 2016. The Company also leases warehouse space in LaSalle, Illinois and in Chesapeake, Virginia. The Company’s Philippines subsidiary leases office space under an agreement through April 2020. Facility rent expense for fiscal year ended 2016 , 2015 and 2014 was $1,670 , $1,555 and $1,895 , respectively. The Company’s facility rent expense did not include any amounts charged from a related party during fiscal years 2016 and 2015 , and was inclusive of amounts charged from a related party of $378 for fiscal 2014 . On February 4, 2016, the Company entered into a new lease for its distribution center located in Chesapeake, Virginia. The Lease between the Company and Liberty Property Limited Partnership is for approximately 159,294 square feet. The initial three -year term of the Lease commenced on July 1, 2016. The Company is obligated to pay approximately $640 in annual base rent, which shall increase by approximately 2.5% each year. The Company is also obligated to pay certain operating expenses set forth in the Lease. Pursuant to the Lease, the Company has the option to extend the Lease for an additional three -year term, with certain increases in base rent. The monthly base rent commitment was $53 as of December 31, 2016 . In January 2010, the Company’s Philippines subsidiary entered into a new lease agreement that accommodates the Company’s Philippines workforce into one office building. Under the terms of the lease agreement, effective March 1, 2010, the monthly rent was approximately $25 , and became subject to 5% annual escalation beginning on the 3 rd year of the lease term. The lease renewed for a sixty month term upon mutual agreement of both parties during 2015. As described in detail under “Note 4 – Property and Equipment Net” , on April 17, 2013 , the Company entered into a sale lease-back agreement with STORE Master Funding III, LLC (“STORE”) whereby we leased back our facility located in LaSalle, Illinois for our continued use as an office, retail and warehouse facility for storage, sale and distribution of automotive parts, accessories and related items for 20 years commencing upon the execution of the lease and terminating on April 30, 2033 . The related assets for the sale lease-back land and building is represented by the amount included in leased facility in the summary above. The Company’s initial base annual rent is $853 for the first year (“Base Rent Amount”), after which the rental amount will increase annually on May 1 by the lesser of 1.5% or 1.25 times the change in the Consumer Price Index as published by the U.S. Department of Labor’s Bureau of Labor Statistics, except that in no event will the adjusted annual rental amount fall below the Base Rent Amount. We were not required to pay any security deposit. Under the terms of the lease, we are required to pay all taxes associated with the lease, pay for any required maintenance on the property, maintain certain levels of insurance and indemnify STORE for losses incurred that are related to our use or occupancy of the property. The lease was accounted for as a capital lease and the $376 excess of the net proceeds over the net carrying amount of the property is amortized in interest expense on a straight-line basis over the lease term of 20 years. As of December 31, 2016 , the net carrying value of all capital leased assets included in property and equipment was $9,033 . Minimum lease commitments under non-cancelable operating leases as of December 31, 2016 are as follows: 2017 $ 1,453 2018 1,493 2019 1,200 2020 550 2021 — Total 4,696 Capital lease commitments as of December 31, 2016 were as follows: Capital Lease Commitments Less: Interest Payments Principal Obligations 2017 $ 1,285 $ 743 $ 542 2018 1,319 721 598 2019 1,304 690 614 2020 1,129 657 472 2021 962 630 332 2022 onwards 11,948 4,194 7,754 Total $ 17,947 $ 7,635 $ 10,312 Legal Matters Asbestos . A wholly-owned subsidiary of the Company, Automotive Specialty Accessories and Parts, Inc. and its wholly-owned subsidiary WAG, are named defendants in several lawsuits involving claims for damages caused by installation of brakes during the late 1960’s and early 1970’s that contained asbestos. WAG marketed certain brakes, but did not manufacture any brakes. WAG maintains liability insurance coverage to protect its and the Company’s assets from losses arising from the litigation and coverage is provided on an occurrence rather than a claims made basis, and the Company is not expected to incur significant out-of-pocket costs in connection with this matter that would be material to its consolidated financial statements. The Company is subject to legal proceedings and claims which arise in the ordinary course of its business. As of the date hereof, the Company believes that the final disposition of such matters will not have a material adverse effect on the financial position, results of operations or cash flow of the Company. The Company maintains liability insurance coverage to protect the Company’s assets from losses arising out of or involving activities associated with ongoing and normal business operations.

Employee Retirement Plan and De

Employee Retirement Plan and Deferred Compensation Plan	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Employee Retirement Plan and Deferred Compensation Plan	Employee Retirement Plan and Deferred Compensation Plan Effective February 17, 2006, the Company adopted a 401(k) defined contribution retirement plan covering all full time employees who have completed one month of service. The Company may, at its sole discretion, match fifty cents per dollar up to 6% of each participating employee’s salary. The Company’s contributions vest in annual installments over three years . Discretionary contributions made by the Company totaled $289 , $280 and $256 for fiscal year 2016 , 2015 and 2014 , respectively. In January 2010, the Company adopted the U.S. Auto Parts Network, Inc. Management Deferred Compensation Plan (the “Deferred Compensation Plan”), for the purpose of providing highly compensated employees a program to meet their financial planning needs. The Deferred Compensation Plan provides participants with the opportunity to defer up to 90% of their base salary and up to 100% of their annual earned bonus, all of which, together with the associated investment returns, are 100% vested from the outset. The Deferred Compensation Plan, which is designed to be exempt from most provisions of the Employee Retirement Security Act of 1974, is informally funded by the Company through the purchase of Company-owned life insurance policies with the Company (employer) as the owner and beneficiary, in order to preserve the tax-deferred savings advantages of a non-qualified plan. The plan assets are the cash surrender value of the Company-owned life insurance policies and not associated with the deferred compensation liability. The deferred compensation liabilities (consisting of employer contributions, employee deferrals and associated earnings and losses) are general unsecured obligations of the Company. Liabilities under the Deferred Compensation Plan are recorded at amounts due to participants, based on the fair value of participants’ selected investments. The Company may at its discretion contribute certain amounts to eligible employee accounts. In January 2010, the Company began to contribute 50% of the first 2% of participants’ eligible contributions into their Deferred Compensation Plan accounts. In September 2010, the Company established and transferred its ownership to a rabbi trust to hold the Company-owned life insurance policies. As of December 31, 2016 , the assets and associated liabilities of the Deferred Compensation Plan were $676 and $688 , respectively, and were $781 and $558 , respectively, as of January 2, 2016 and are included in other non-current assets, other current liabilities and other non-current liabilities in our consolidated balance sheets. For fiscal year 2016 , the change in the associated liabilities include the employee contributions of $156 , the Company contributions of $69 , offset by unrealized earnings of $41 and distributions of $23 . For fiscal year 2015 , the associated liabilities primarily include the employee contributions of $102 and the Company contributions of $27 offset by unrealized losses of $13 and distributions of $307 . For fiscal year 2016 , included in other income, the Company recorded a net loss of $2 for the change in the cash surrender value of the Company-owned life insurance policies. For fiscal year 2015 , included in other income, the Company recorded a net loss of $73 for the change in the cash surrender value of the Company-owned life insurance policies.

Restructuring Costs

Restructuring Costs	12 Months Ended
	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Costs Fiscal 2014 On June 25, 2014, the Company committed to a plan to permanently close its distribution facility located in Carson, California (the “Carson Distribution Facility”) effective July 25, 2014. The Company consolidated the Carson Distribution Facility’s distribution and warehousing operations into the Company’s existing distribution facilities located in LaSalle, Illinois and Chesapeake, Virginia. This consolidation was part of the Company’s continued efforts for simplification and improved efficiencies. The closure of the Carson Distribution Facility resulted in a head count reduction of approximately 77 employees. The following table summarizes the charges related to the restructure recognized during the fiscal year ended January 3, 2015: Employee severance $ 526 Accounts receivable allowance 73 Relocation costs (employee and equipment) 127 Inventory transfers 411 Total restructuring costs $ 1,137 Substantially all of the unsold inventory in the Carson Distribution Facility on the date of closure was moved to the remaining two warehouses. Costs related to inventory transfers were recorded to cost of sales. A charge for $130 was taken for inventory that was not deemed economical to transfer. Additionally, due to expected future capacity constraints, the Company reduced the sales price of certain inventory resulting in a charge of $767 . The aggregate charge of $897 was recorded to cost of sales. The severance charges and relocation costs were included in fulfillment expense. Severance charges were reduced by $26 in the fourth quarter of 2014 as certain employees were able to find employment before they became eligible for severance benefits. As of January 3, 2015, there was no severance payable.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions The Company leased its Carson warehouse from Nia Chloe, LLC (“Nia Chloe”), a member of which, Sol Khazani, is one of our board of directors. Lease payments and expenses associated with this related party arrangement totaled $378 for fiscal year 2014. The lease expired during fiscal 2014 and was not renewed. On October 8, 2014, Oak Investment Partners XI, L.P. ("Oak") and the Sol Khazani Living Trust ("Trust") purchased 1.5 million and 0.5 million shares of AutoMD common stock, respectively, at a purchase price of $1.00 per share. Fredric W. Harman and Sol Khazani, each a current director of the Company, are affiliated with Oak and the Trust, respectively. On March 6, 2017, AutoMD entered into a dissolution agreement with each of Oak Investment Partners XI, Limited Partnership (“Oak”) and the Sol Khazani Living Trust (the “Trust”), pursuant to which AutoMD redeemed 1.5 million and 0.5 million shares of its common stock, respectively, for a purchase price of $895 and $299 , respectively. In connection with the dissolution agreement, each of the prior investor agreements entered into between AutoMD, on the one hand, and Oak and the Trust, on the other, were terminated. Fredric W. Harman and Sol Khazani, each a current director of the Company and AutoMD, are affiliated with Oak and the Trust, respectively. The Company has entered into indemnification agreements with the Company’s directors and executive officers. These agreements require the Company to indemnify these individuals to the fullest extent permitted under law against liabilities that may arise by reason of their service to the Company, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified.

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Information (Unaudited)	Quarterly Information (Unaudited) The following quarterly information (in thousands, except per share data) includes all adjustments which management considers necessary for a fair presentation of such information. For interim quarterly financial statements, the provision for income taxes is estimated using the best available information for projected results for the entire year. Quarter Ended Quarter Ended April 2, 2016 July 2, 2016 Oct. 1, 2016 Dec. 31, 2016 April 4, 2015 July 4, 2015 Oct. 3, 2015 Jan. 2, 2016 Consolidated Statement of Income Data: Net sales $ 80,806 $ 78,055 $ 73,515 $ 71,195 $ 76,388 $ 76,462 $ 70,648 $ 67,593 Gross profit 24,592 23,754 22,414 21,522 21,478 20,868 21,042 20,046 Income (loss) from operations 1,182 865 (84 ) (1,573 ) (18 ) (1,107 ) (222 ) (708 ) Income (loss) before income taxes 841 625 (367 ) (1,901 ) (368 ) (1,369 ) (491 ) (1,007 ) Net income (loss) 990 681 (360 ) (1,914 ) (316 ) (1,022 ) (288 ) (798 ) Net loss attributable to noncontrolling interests (262 ) (253 ) (258 ) (561 ) (256 ) (247 ) (296 ) (344 ) Net income (loss) attributable to U.S. Auto Parts $ 1,252 $ 934 $ (102 ) $ (1,353 ) $ (60 ) $ (775 ) $ 8 $ (454 ) Basic net income (loss) per share as reported and adjusted $ 0.03 $ 0.03 $ 0.00 $ (0.04 ) $ 0.00 $ (0.02 ) $ 0.00 $ (0.01 ) Diluted net income (loss) per share as reported and adjusted $ 0.03 $ 0.02 $ 0.00 $ (0.04 ) $ 0.00 $ (0.02 ) $ 0.00 $ (0.01 ) Shares used in computation of basic net income (loss) per share as reported and adjusted 34,497 34,753 34,932 34,878 33,720 33,963 34,018 34,084 Shares used in computation of diluted net income (loss) per share as reported and adjusted 39,359 40,007 34,932 34,878 33,720 33,963 34,018 34,084

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information As described in Note 1 above, the Company operates in two reportable segments identified as Base USAP, which is the core auto parts business, and AutoMD, an online automotive repair source. Segment information is prepared on the same basis that our chief executive officer, who is our chief operating decision maker, manages the segments, evaluates financial results, and makes key operating decisions. Management evaluates the performance of its operating segments based on net sales, gross profit and loss from operations. The accounting policies of the operating segments are the same as those described in Note 1. Operating income represents earnings before other income, interest expense and income taxes. The identifiable assets by segment disclosed in this note are those assets specifically identifiable within each segment. Summarized segment information for our continuing operations from the two reportable segments for the periods presented is as follows (in thousands): Base USAP AutoMD Consolidated Fiscal year ended December 31, 2016 Net sales $ 303,324 $ 247 $ 303,571 Gross profit 92,047 235 92,282 Operating costs (1) 87,782 4,110 91,892 Income (loss) from operations 4,265 (3,875 ) 390 Capital expenditures 5,414 939 6,353 Depreciation and amortization 6,351 1,159 7,510 Total assets, net of accumulated depreciation 78,094 4,040 82,134 Fiscal year ended January 2, 2016 Net sales $ 290,833 $ 258 $ 291,091 Gross profit 83,176 258 83,434 Operating costs (1) 82,044 3,445 85,489 Loss from operations 1,132 (3,187 ) (2,055 ) Capital expenditures 6,701 1,079 7,780 Depreciation and amortization 6,141 1,369 7,510 Total assets, net of accumulated depreciation 78,092 5,664 83,756 Fiscal year ended January 3, 2015 Net sales $ 283,211 $ 297 $ 283,508 Gross profit 78,153 297 78,450 Operating costs (1) 81,887 2,475 84,362 Loss from operations (3,734 ) (2,178 ) (5,912 ) Capital expenditures 4,237 1,319 5,556 Depreciation and amortization 7,230 1,693 8,923 Total assets, net of accumulated depreciation 74,414 8,493 82,907 (1) Operating costs for AutoMD primarily consist of depreciation on fixed assets and personnel costs. The following table summarizes the approximate distribution of Base USAP revenue by product type. 2016 2015 2014 Private Label Collision 51% 48% 43% Engine 15% 14% 13% Performance 1% 1% 1% Branded Collision 2% 2% 2% Engine 12% 14% 16% Performance 19% 21% 25% Total 100% 100% 100%

AutoMD

AutoMD	12 Months Ended
	Dec. 31, 2016
Noncontrolling Interest [Abstract]
AutoMD	AutoMD On October 8, 2014, AutoMD entered into a Common Stock Purchase Agreement ("Purchase Agreement") to sell an aggregate of seven million shares of AutoMD common stock at a purchase price of $1.00 per share to third-party investors and investors that are affiliated with two of our board members. On October 19, 2016, the Company purchased two million shares of AutoMD common stock at a purchase price of $1.00 per share pursuant to its funding milestone obligation under the Purchase Agreement. On January 26, 2017, AutoMD entered into a redemption agreement with third-party investors to redeem an aggregate of five million shares of AutoMD common stock for a purchase price of $1,292 . On March 6, 2017, following a review of various business and strategic options, AutoMD entered into a dissolution agreement with its two remaining minority stockholders pursuant to which the Company repurchased the remaining shares of common stock from minority stockholders for a purchase price of $1,194 in consideration for terminating the prior investor agreements. Following the redemptions, AutoMD filed for dissolution and all of the remaining assets of AutoMD will be distributed to the Company, except for certain cash reserved for creditors of AutoMD. These actions will likely result in the Company presenting AutoMD as discontinued operations. The Company estimates that we will incur charges related to severance, other contractual obligations and premium charges related to repurchasing shares from minority stockholders that will impact cash during the first quarter of fiscal 2017. AutoMD intends to continue to operate its media business, and accordingly, the Company anticipates continued revenue associated with the media business.

Summary of Significant Accoun23

Summary of Significant Accounting Policies and Nature of Operations (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Fiscal Year	The Company’s fiscal year is based on a 52/53 week fiscal year ending on the Saturday closest to December 31. The fiscal years ended December 31, 2016 (fiscal year 2016 ) and January 2, 2016 (fiscal year 2015 ) are both 52 week periods. The fiscal year ended January 3, 2015 (fiscal year 2014 ) is a 53 week period.
Principles of Consolidation	The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and its subsidiaries in which it has a controlling interest. On October 8, 2014, AutoMD, Inc. ("AutoMD") sold seven million shares of its common stock to third-party investors, reducing the Company’s ownership interest in AutoMD to 64.1% . In October 2016, the Company purchased an additional two million shares of AutoMD common stock pursuant to its funding milestone obligations under the common stock purchase agreement, increasing the Company's ownership interest in AutoMD to 67.4% . On January 26, 2017, AutoMD entered into redemption agreements with certain third-party investors to redeem an aggregate of five million shares of AutoMD common stock for a purchase price of $1,292 . The redemption agreements increased the Company's ownership interest in AutoMD to 87.9% of AutoMD's outstanding common stock. The remaining 12.1% of AutoMD controlled by third-party investors was repurchased on March 6, 2017. The Company reports noncontrolling interests in consolidated entities as a component of equity separate from the Company’s equity. All inter-company transactions between and among the Company and its consolidated subsidiaries have been eliminated in consolidation.
Basis of Presentation	During fiscal year 2016 , the Company’s revenues increased 4.3% from fiscal 2015 after having increased in fiscal year 2015 by 2.7% from fiscal year 2014 . In fiscal year 2016 , the Company generated net income of $731 , after incurring net losses of $1,281 and $6,879 in fiscal years 2015 and 2014 , respectively. Based on our current operating plan, we believe that our existing cash, cash equivalents, short-term investments, cash flows from operations and available debt financing will be sufficient to finance our operational cash needs through at least the next twelve months. Should the Company’s operating results not meet expectations in 2017 , it could negatively impact our liquidity as we may not be able to provide positive cash flows from operations in order to meet our working capital requirements. We may need to borrow additional funds from our credit facility, which under certain circumstances may not be available, sell assets or seek additional equity or additional debt financing in the future. There can be no assurance that we would be able to raise such additional financing or engage in such additional asset sales on acceptable terms, or at all. If revenues were to decline and we incur net losses because our strategies to return to consistent profitability are not successful or otherwise, and if we are not able to raise adequate additional financing or proceeds from asset sales to continue to fund our ongoing operations, we will need to defer, reduce or eliminate significant planned expenditures, restructure or significantly curtail our operations.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates made by management include, but are not limited to, those related to revenue recognition, uncollectible receivables, the valuation of short-term investments, valuation of inventory, valuation of deferred tax assets and liabilities, valuation of intangible and other long-lived assets, recoverability of software development costs, contingencies and share-based compensation expense that results from estimated grant date fair values and vesting of issued equity awards. Actual results could differ from these estimates.
Statement of Cash Flows	The net change in the Company’s book overdraft is presented as an operating activity in the consolidated statement of cash flows. The book overdraft represents a credit balance in the Company’s general ledger but the Company has a positive bank account balance.
Cash and Cash Equivalents	The Company considers all money market funds and short-term investments purchased with original maturities of ninety days or less to be cash equivalents.
Fair Value of Financial Instruments	Financial instruments that are not measured at fair value include accounts receivable, accounts payable and debt. Refer to “ Note 3 – Fair Value Measurements ” for additional fair value information. If the Company’s revolving loan payable (see “Note 6 – Borrowings” ) had been measured at fair value, it would be categorized in Level 2 of the fair value hierarchy, as the estimated value would be based on the quoted market prices for the same or similar issues or on the current rates available to the Company for debt of the same or similar terms. The carrying values of cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their short-term maturities. Short-term investments are carried at fair value. Based on the borrowing rates currently available to the Company for bank loans with similar terms and average maturities, the fair value of our revolving loan payable, classified as current liability in our consolidated balance sheet, approximates its carrying amount because the interest rate is variable.
Accounts Receivable and Concentration of Credit Risk	Accounts receivable are stated net of allowance for doubtful accounts. The allowance for doubtful accounts is determined primarily on the basis of past collection experience and general economic conditions. The Company determines terms and conditions for its customers primarily based on the volume purchased by the customer, customer creditworthiness and past transaction history. Concentrations of credit risk are limited to the customer base to which the Company’s products are sold. The Company does not believe significant concentrations of credit risk exist.
Investments	Short-term investments are comprised of closed-end funds primarily invested in mutual funds that hold government bonds and stock and short-term money market funds. Mutual funds are classified as short-term investments available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined. All of the Company’s marketable securities and investments are subject to a periodic impairment review. The Company recognizes an impairment charge when a decline in the fair value of its investments below the cost basis is judged to be other-than-temporary. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time and extent to which the fair value has been less than the Company’s cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value.
Inventory	Inventories consist of finished goods available-for-sale and are stated at the lower of cost or market value, determined using the first-in first-out (“FIFO”) method. The Company purchases inventory from suppliers both domestically and internationally, and routinely enters into supply agreements with Asia-Pacific based suppliers of private label products and U.S.–based suppliers who are primarily drop-ship vendors. The Company believes that its products are generally available from more than one supplier and seeks to maintain multiple sources for its products, both internationally and domestically. The Company primarily purchases products in bulk quantities to take advantage of quantity discounts and to ensure inventory availability. Inventory is reported at the lower of cost or market, adjusted for slow moving, obsolete or scrap product.
Website and Software Development Costs	The Company capitalizes certain costs associated with website and software developed for internal use according to ASC 350-50 - Intangibles – Goodwill and Other – Website Development Costs and ASC 350-40 Intangibles – Goodwill and Other – Internal-Use Software , when both the preliminary project design and testing stage are completed and management has authorized further funding for the project, which it deems probable of completion and to be used for the function intended. Capitalized costs include amounts directly related to website and software development such as payroll and payroll-related costs for employees who are directly associated with, and who devote time to, the internal-use software project. Capitalization of such costs ceases when the project is substantially complete and ready for its intended use. These amounts are amortized on a straight-line basis over two to three years once the software is placed into service.
Long-Lived Assets and Intangibles Subject to Amortization	The Company accounts for the impairment and disposition of long-lived assets, including intangibles subject to amortization, in accordance with ASC - 360 Property, Plant and Equipment (“ASC 360”) . Management assesses potential impairments whenever events or changes in circumstances indicate that the carrying value of an asset or asset group may not be recoverable. An impairment loss will result when the carrying value exceeds the undiscounted cash flows estimated to result from the use and eventual disposition of the asset or asset group. Impairment losses will be recognized in operating results to the extent that the carrying value exceeds the discounted future cash flows estimated to result from the use and eventual disposition of the asset or asset group. The Company continually uses judgment when applying these impairment rules to determine the timing of the impairment tests, undiscounted cash flows used to assess impairments, and the fair value of a potentially impaired asset or asset group. The reasonableness of our judgments could significantly affect the carrying value of our long-lived assets.
Deferred Catalog Expenses	Deferred catalog expenses consist of third-party direct costs including primarily creative design, paper, printing, postage and mailing costs for all Company direct response catalogs. Such costs are capitalized as deferred catalog expenses and are amortized over their expected future benefit period. Each catalog is fully amortized within nine months .
Deferred Financing Costs	Deferred financing costs are being amortized over the life of the loan using the straight-line method as it is not significantly different from the effective interest method.
Revenue Recognition	The Company recognizes revenue from product sales and shipping revenues, net of promotional discounts and return allowances, when the following revenue recognition criteria are met: persuasive evidence of an arrangement exists, both title and risk of loss or damage have transferred, delivery has occurred, the selling price is fixed or determinable, and collectability is reasonably assured. The Company retains the risk of loss or damage during transit, therefore, revenue from product sales is recognized at the delivery date to customers. Return allowances, which reduce product revenue by the Company’s best estimate of expected product returns, are estimated using historical experience. Revenue from sales of advertising is recorded when performance requirements of the related advertising program agreement are met. For each of the fiscal years ended 2016 , 2015 and 2014 , the advertising revenue represented approximately 1% , of our total revenue. The Company evaluates the criteria of ASC 605-45 - Revenue Recognition Principal Agent Considerations in determining whether it is appropriate to record the gross amount of product sales and related costs or the net amount earned as commissions. Generally, when the Company is the primary party obligated in a transaction, the Company is subject to inventory risk, has latitude in establishing prices and selecting suppliers, or has several but not all of these indicators, revenue is recorded at gross. Payments received prior to the delivery of goods to customers are recorded as deferred revenue. The Company periodically provides incentive offers to its customers to encourage purchases. Such offers include current discount offers, such as percentage discounts off current purchases and other similar offers. Current discount offers, when accepted by the Company’s customers, are treated as a reduction to the purchase price of the related transaction. Sales discounts are recorded in the period in which the related sale is recognized. Sales return allowances are estimated based on historical amounts and are recorded upon recognizing the related sales. Credits are issued to customers for returned products.
Cost of Sales	Cost of sales consists of the direct costs associated with procuring parts from suppliers and delivering products to customers. These costs include direct product costs, outbound freight and shipping costs, warehouse supplies and warranty costs, partially offset by purchase discounts and cooperative advertising. Total freight and shipping expense included in cost of sales for fiscal year 2016 , 2015 and 2014 was $41,937 , $41,250 , and $40,428 , respectively. Depreciation and amortization expenses are excluded from cost of sales and included in marketing, general and administrative and fulfillment expenses.
Warranty Costs	The Company or the vendors supplying its products provide the Company’s customers limited warranties on certain products that range from 30 days to lifetime. Historically, the Company’s vendors have been the party primarily responsible for warranty claims. Standard product warranties sold separately by the Company are recorded as deferred revenue and recognized ratably over the life of the warranty, ranging from one to five years . The Company also offers extended warranties that are imbedded in the price of selected private label products sold. The product brands that include the extended warranty coverage are offered at three different service levels: (a) a five year unlimited product replacement, (b) a five year one-time product replacement, and (c) a three year one-time product replacement. Warranty costs relating to merchandise sold under warranty not covered by vendors are estimated and recorded as warranty obligations at the time of sale based on each product’s historical return rate and historical warranty cost. The standard and extended warranty obligations are recorded as warranty liabilities and included in other current liabilities in the consolidated balance sheets.
Marketing Expense	Marketing costs, including advertising, are expensed as incurred. The majority of advertising expense is paid to internet search engine service providers and internet commerce facilitators. For fiscal year 2016 , 2015 and 2014 , the Company recognized advertising costs of $22,616 , $20,251 and $18,485 , respectively. Marketing costs also include depreciation and amortization expense and share-based compensation expense.
General and Administrative Expense	General and administrative expense consists primarily of administrative payroll and related expenses, merchant processing fees, legal and professional fees and other administrative costs. General and administrative expense also includes depreciation and amortization expense and share-based compensation expense.
Fulfillment Expense	Fulfillment expense consists primarily of payroll and related costs associated with warehouse employees and the Company’s purchasing group, facilities rent, building maintenance, depreciation and other costs associated with inventory management and wholesale operations. Fulfillment expense also includes share-based compensation expense.
Technology Expense	Technology expense consists primarily of payroll and related expenses of our information technology personnel, the cost of hosting the Company’s servers, communications expenses and Internet connectivity costs, computer support and software development amortization expense. Technology expense also includes share-based compensation expense.
Share-Based Compensation	The Company accounts for share-based compensation in accordance with ASC 718 - Compensation – Stock Compensation (“ASC 718”). All share-based payment awards issued to employees are recognized as share-based compensation expense in the financial statements based on their respective grant date fair values, and are recognized within the statement of comprehensive income or loss as marketing, general and administrative, fulfillment or technology expense, based on employee departmental classifications. Under this standard, compensation expense for both time-based and performance-based restricted stock units is based on the closing stock price of our common shares on the date of grant, and is recognized on a straight-line basis over the requisite service period. Compensation expense for performance-based awards is measured based on the amount of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. Compensation expense for stock options is based on the fair value estimated on the date of grant using an option pricing model, and is recognized over the vesting period of three to four years. The Company currently uses the Black-Scholes option pricing model to estimate the fair value of share-based payment awards for such stock options, which is affected by the Company’s stock price and a number of assumptions, including expected volatility, expected life, risk-free interest rate and expected dividends. The Company incorporates its own historical volatility into the grant-date fair value calculations for the stock options. The expected term of an award is based on combining historical exercise data with expected weighted time outstanding. Expected weighted time outstanding is calculated by assuming the settlement of outstanding awards is at the midpoint between the remaining weighted average vesting date and the expiration date. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected life of awards. The dividend yield assumption is based on the Company’s expectation of paying no dividends on its common stock. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures significantly differ from those estimates. The Company considers many factors when estimating expected forfeitures, including employee class, economic environment, and historical experience. The Company accounts for equity instruments issued in exchange for the receipt of services from non-employee directors in accordance with the provisions of ASC 718. The Company accounts for equity instruments issued in exchange for the receipt of goods or services from other than employees in accordance with ASC 505-50 - Equity-Based Payments to Non-Employees . Costs are measured at the estimated fair market value of the consideration received or the estimated fair value of the equity instruments issued, whichever is more reliably measurable. The value of equity instruments issued for consideration other than employee services is determined on the earlier of a performance commitment or completion of performance by the provider of goods or services. Equity instruments awarded to non-employees are periodically re-measured as the underlying awards vest unless the instruments are fully vested, immediately exercisable and non-forfeitable on the date of grant. The Company accounts for modifications to its share-based payment awards in accordance with the provisions of ASC 718. Incremental compensation cost is measured as the excess, if any, of the fair value of the modified award over the fair value of the original award immediately before its terms are modified, measured based on the share price and other pertinent factors at that date, and is recognized as compensation cost on the date of modification (for vested awards) or over the remaining service (vesting) period (for unvested awards). Any unrecognized compensation cost remaining from the original award is recognized over the vesting period of the modified award.
Other Income, net	Other income, net consists of miscellaneous income or expense such as gains/losses from disposition of assets, and interest income comprised primarily of interest income on investments.
Interest Expense	Interest expense consists primarily of interest expense on our outstanding loan balance, deferred financing cost amortization, and capital lease interest.
Income Taxes	The Company accounts for income taxes in accordance with ASC 740 - Income Taxes (“ASC 740”). Under ASC 740, deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. When appropriate, a valuation allowance is established to reduce deferred tax assets, which include tax credits and loss carry forwards, to the amount that is more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences and carryforwards, taxable income in prior carryback years, tax planning strategies and recent financial operations. The Company utilizes a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. The Company considers many factors when evaluating and estimating our tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. As of December 31, 2016 , the Company had no material unrecognized tax benefits, interest or penalties related to federal and state income tax matters. The Company’s policy is to record interest and penalties as income tax expense.
Taxes Collected from Customers and Remitted to Governmental Authorities	We present taxes collected from customers and remitted to governmental authorities on a net basis in accordance with the guidance on ASC 605-45-50-3 - Taxes Collected from Customers and Remitted to Governmental Authorities .
Leases	The Company analyzes lease agreements for operating versus capital lease treatment in accordance with ASC 840 Leases . Rent expense for leases designated as operating leases is expensed on a straight-line basis over the term of the lease. For capital leases, the present value of future minimum lease payments at the inception of the lease is reflected as a capital lease asset and a capital lease payable in the consolidated balance sheets. Amounts due within one year are classified as current liabilities and the remaining balance as non-current liabilities.
Foreign Currency Translation	For each of the Company’s foreign subsidiaries, the functional currency is its local currency. Assets and liabilities of foreign operations are translated into U.S. dollars using the current exchange rates, and revenues and expenses are translated into U.S. dollars using average exchange rates. The effects of the foreign currency translation adjustments are included as a component of accumulated other comprehensive income or loss in the Company’s consolidated balance sheets.
Comprehensive Income	The Company reports comprehensive income or loss in accordance with ASC 220 - Comprehensive Income . Accumulated other comprehensive income or loss, included in the Company’s consolidated balance sheets, includes foreign currency translation adjustments related to the Company’s foreign operations, actuarial gains and losses on the Company's defined benefit plan and unrealized holding gains and losses from available-for-sale marketable securities and investments. The Company presents the components of net income or loss and other comprehensive income or loss in its consolidated statements of comprehensive operations.
Segment Data	The Company operates in two reportable operating segments. The criteria we use to identify operating segments are primarily the nature of the products we sell or services we provide and the consolidated operating results that are regularly reviewed by our chief operating decision maker to assess performance and make operating decisions. We identified two reportable operating segments, Base USAP, which is the core auto parts business, and AutoMD, an online automotive repair source, in accordance with ASC 280 - Segment Reporting (“ASC 280”) .
Recently Adopted Accounting Pronouncements/Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In July 2015, the FASB issued Accounting Standards Update No. 2015-11, “ Simplifying the Measurement of Inventory ,” (“ASU 2015-11”) which requires an entity to measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable cost of completion, disposal, and transportation. The new standard is effective for fiscal years beginning after December 15, 2016, and interim periods within fiscal years beginning after December 15, 2017. The amendments in ASU 2015-11 should be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. This guidance was adopted by us in the fourth quarter of 2016, and it did not have a material impact on our consolidated financial statements. In November 2014, the FASB issued Accounting Standards Update No. 2014-16 " Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity ". The objective of this Update is to eliminate the use of different methods in practice and thereby reduce existing diversity under GAAP in the accounting for hybrid financial instruments issued in the form of a share. The new standard is effective for fiscal years beginning after December 15, 2015. Early adoption is permitted. The Company has adopted ASU 2014-16 and it did not have a material impact on our financial statements. Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2016-09, “ Compensation - Stock Compensation ” (“ASU 2016-09”). The objective of this update is to simplify accounting related to stock compensation. The new standard is effective for fiscal years beginning after December 15, 2016, and interim periods within those annual periods. The Company is evaluating the financial impacts that ASU 2016-09 will have on the consolidated financial statements and related disclosures, and it is not expected to have a material impact. In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2016-02, “ Leases ” (“ASU 2016-02”). The objective of this update is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The new standard is effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. Early adoption is permitted. The Company is evaluating the effect that ASU 2016-02 will have on the consolidated financial statements and related disclosures. The Company has not yet selected a transition method, however, due to the limited nature of our lease activity, it is not expected to have a material impact. In May 2014, the FASB issued Accounting Standards Update No. 2014-9, “ Revenue from Contracts with Customers ,” (“ASU 2014-9”) which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This guidance will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for fiscal years beginning after December 15, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-9 will have on the consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has the effect of the standard on ongoing financial reporting been determined, however, due to the nature of our revenue streams it is not expected to have a material impact.

Summary of Significant Accoun24

Summary of Significant Accounting Policies and Nature of Operations (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Allowance for Sales Returns and Allowance for Doubtful Accounts	The following table provides an analysis of the allowance for sales returns and the allowance for doubtful accounts (in thousands): Balance at Beginning of Period Charged to Revenue, Cost or Expenses Deductions Balance at End of Period Fifty-Two Weeks Ended December 31, 2016 Allowance for sales returns $ 1,009 $ 23,804 $ (23,876 ) $ 937 Allowance for doubtful accounts 17 254 (235 ) 36 Fifty-Two Weeks Ended January 2, 2016 Allowance for sales returns $ 897 $ 23,655 $ (23,543 ) $ 1,009 Allowance for doubtful accounts 41 29 (53 ) 17 Fifty-Three Weeks Ended January 3, 2015 Allowance for sales returns $ 893 $ 24,907 $ (24,903 ) $ 897 Allowance for doubtful accounts 213 64 (236 ) 41
Aggregate Warranty Liabilities	For the fiscal year 2016 and 2015 , the activity in the aggregate warranty liabilities was as follows (in thousands): December 31, 2016 January 2, 2016 Warranty liabilities, beginning of period $ 110 $ 218 Adjustments to preexisting warranty liabilities — (109 ) Additions to warranty liabilities 918 53 Reductions to warranty liabilities (139 ) (52 ) Warranty liabilities, end of period $ 889 $ 110

Short-term investments (Tables)

Short-term investments (Tables)	12 Months Ended
	Dec. 31, 2016
Investments Schedule [Abstract]
Securities and Investments, Recorded at Fair Value	As of December 31, 2016 , the Company held the following short-term investments, recorded at fair value: Amortized Cost Unrealized Fair Value Gains Losses Mutual funds (1) $ 32 $ — $ (2 ) $ 30 As of January 2, 2016 , the Company held the following short-term investments, recorded at fair value: Amortized Cost Unrealized Fair Value Gains Losses Mutual funds (1) $ 65 $ — $ — $ 65 (1) Mutual funds are classified as short-term investments available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Financial Assets Valued on Recurring Basis	The following table represents our fair value hierarchy and the valuation techniques used for financial assets measured at fair value on a recurring basis: December 31, 2016 Total Level 1 Level 2 Level 3 Valuation Techniques Assets: Cash and cash equivalents (1) $ 6,643 $ 6,643 $ — $ — (a) Short-term investments – mutual funds (2) 30 30 — — (a) $ 6,673 $ 6,673 $ — $ — January 2, 2016 Total Level 1 Level 2 Level 3 Valuation Techniques Assets: Cash and cash equivalents (1) $ 5,537 $ 5,537 $ — $ — (a) Short-term investments – mutual funds (2) 65 65 — — (a) $ 5,602 $ 5,602 $ — $ — (1) Cash equivalents consist primarily of money market funds and short-term investments with original maturity dates of three months or less at the date of purchase, for which the Company determines fair value through quoted market prices. (2) Short-term investments consist of mutual funds, classified as available-for-sale and recorded at fair market value, based on quoted prices of identical assets that are trading in active markets as of the end of the period for which the values are determined.

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following at December 31, 2016 and January 2, 2016 : December 31, 2016 January 2, 2016 Land $ 630 $ 630 Building 8,877 8,877 Machinery and equipment 12,368 12,334 Computer software (purchased and developed) and equipment 26,717 27,083 Vehicles 98 136 Leasehold improvements 1,007 1,474 Furniture and fixtures 1,030 1,039 Construction in process 1,539 1,588 52,266 53,161 Less accumulated depreciation and amortization (35,788 ) (34,730 ) Property and equipment, net $ 16,478 $ 18,431
Summary of Estimated Useful Lives of Property and Equipment	Depreciation of property and equipment is provided using the straight-line method for financial reporting purposes, at rates based on the following estimated useful lives: Years Machinery and equipment 2 - 5 Computer software (purchased and developed) 2 - 3 Computer equipment 2 - 5 Vehicles 3 - 5 Leasehold improvements* 3 - 5 Furniture and fixtures 3 - 7 Facility subject to capital lease 20 * The estimated useful life is the lesser of 3 - 5 years or the lease term, whichever is shorter.

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	Intangible assets consisted of the following at December 31, 2016 and January 2, 2016 : Useful Life December 31, 2016 January 2, 2016 Gross Carrying Amount Accumulated Amort. and Impairment Net Carrying Amount Gross Carrying Amount Accum. Amort. and Impairment Net Carrying Amount Intangible assets subject to amortization: Product design intellectual property 4 years 2,750 (2,620 ) 130 2,750 (2,361 ) 389 Patent license agreements 3 - 5 years 562 (368 ) 194 562 (219 ) 343 Domain and trade names 10 years 1,407 (762 ) 645 1,407 (663 ) 744 Total $ 4,719 $ (3,750 ) $ 969 $ 4,719 $ (3,243 ) $ 1,476
Summary of Future Estimated Annual Amortization Expense	The following table summarizes the future estimated annual amortization expense for these assets over the next five years and thereafter: 2017 $ 319 2018 185 2019 100 2020 100 2021 100 Thereafter 165 Total $ 969

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Present Value of Net Minimum Payments on Capital Leases	The present value of the net minimum payments on capital leases as of December 31, 2016 is as follows: Total minimum lease payments $ 17,947 Less amount representing interest $ (7,635 ) Present value of net minimum lease payments 10,312 Current portion of capital leases payable (542 ) Capital leases payable, net of current portion $ 9,770 Capital lease commitments as of December 31, 2016 were as follows: Capital Lease Commitments Less: Interest Payments Principal Obligations 2017 $ 1,285 $ 743 $ 542 2018 1,319 721 598 2019 1,304 690 614 2020 1,129 657 472 2021 962 630 332 2022 onwards 11,948 4,194 7,754 Total $ 17,947 $ 7,635 $ 10,312

Stockholders' Equity and Shar30

Stockholders' Equity and Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Changes in Company's Ownership Interest in AutoMD	The table below presents the changes in the Company's ownership interest in AutoMD on the Company's equity as of the dates indicated: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Net income (loss) attributable to U.S. Auto Parts stockholders' $ 731 $ (1,281 ) $ (6,879 ) Transfers (to) from the noncontrolling interest: Increase in U.S. Auto Parts paid-in-capital from sale of AutoMD common stock — — 2,512 Changes from net income (loss) attributable to U.S. Auto Parts stockholders' and transfers to noncontrolling interest $ 731 $ (1,281 ) $ (4,367 )
Summary of Stock Option Activity	The following tables summarize the Company’s stock option activity under the AutoMD 2014 Equity Incentive Plan (the "AMD Plan") for the fiscal years ended, and details regarding the options outstanding and exercisable at December 31, 2016 and January 2, 2016 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Options outstanding, January 2, 2016 1,430 $ 1.00 Granted 10 $ 1.00 Exercised — $ — Cancelled: Forfeited (35 ) $ 1.00 Expired — $ — Options outstanding, December 31, 2016 1,405 $ 1.00 8.20 Vested and expected to vest at December 31, 2016 1,044 $ 1.00 8.19 Options exercisable, December 31, 2016 632 $ 1.00 8.14 Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Options outstanding, January 3, 2015 180 $ 1.00 Granted 1,250 $ 1.00 Exercised — $ — Cancelled: Forfeited — $ — Expired — $ — Options outstanding, January 2, 2016 1,430 $ 1.00 9.19 $ — Vested and expected to vest at January 2, 2016 1,061 $ 1.00 9.19 $ — Options exercisable, January 2, 2016 49 $ 1.00 8.92 $ — The following tables summarizes the Company’s stock option activity for the fiscal years ended, and details regarding the options outstanding and exercisable at December 31, 2016 , and January 2, 2016 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate (1) Options outstanding, January 2, 2016 5,841 $ 2.80 Granted 1,000 $ 3.03 Exercised (442 ) $ 2.06 Cancelled: Forfeited (149 ) $ 2.47 Expired (122 ) $ 7.66 Options outstanding, December 31, 2016 6,128 $ 2.81 5.74 $ 6,561 Vested and expected to vest at December 31, 2016 5,658 $ 2.82 5.49 $ 6,111 Options exercisable, December 31, 2016 4,220 $ 2.92 4.49 $ 4,618 Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate (1) Options outstanding, January 3, 2015 5,281 $ 2.85 Granted 1,315 $ 2.24 Exercised (301 ) $ 1.45 Cancelled: Forfeited (256 ) $ 2.06 Expired (198 ) $ 3.31 Options outstanding, January 2, 2016 5,841 $ 2.80 6.03 $ 4,333 Vested and expected to vest at January 2, 2016 5,285 $ 2.88 5.74 $ 3,853 Options exercisable, January 2, 2016 3,735 $ 3.21 4.54 $ 2,479 (1) These amounts represent the difference between the exercise price and the closing price of U.S. Auto Parts Network, Inc. common stock on December 31, 2016 as reported on the NASDAQ Stock Market, for all options outstanding that have an exercise price currently below the closing price.
Summary of Share-based Compensation from Options, Warrants and Stock Awards	Share-based compensation from options and RSUs, is included in our consolidated statements of comprehensive operations, as follows: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Marketing expense $ 433 $ 518 $ 540 General and administrative expense 2,111 1,614 1,476 Fulfillment expense 450 241 220 Technology expense 137 46 135 Total share-based compensation expense $ 3,131 $ 2,419 $ 2,371
Surrendered Stock Options and New Stock Options Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Assumptions Used	The fair value of the surrendered stock options and the new stock options was estimated on the date of the exchange using the Black-Scholes option pricing model with the following assumptions: Surrendered Stock Options New Stock Options Expected life 1.93 – 6.87 years 5.84 years Risk-free interest rate 0.5% – 2.4% 2.0% Expected volatility 55% – 73% 72% Expected dividend yield —% —%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Assumptions Used	The fair value of each option grant, excluding those options issued from the stock option exchange program as discussed above, was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions for each of the periods ended: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Expected life 5.57 - 5.61 years 5.34 - 5.52 years 5.30 - 5.37 years Risk-free interest rate 1% - 2% 1% - 2% 2% - 2% Expected volatility 60% - 61% 59% - 60% 62% - 68% Expected dividend yield —% —% —%

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of basic and diluted net income (loss) per share: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Net income (loss) per share: Numerator: Net income (loss) attributable to U.S. Auto Parts $ 731 $ (1,281 ) $ (6,879 ) Dividends on Series A Convertible Preferred Stock (241 ) (241 ) (240 ) Net income (loss) available to common shares $ 490 $ (1,522 ) $ (7,119 ) Denominator: Weighted-average common shares outstanding (basic) 34,765 33,946 33,489 Common equivalent shares from common stock options, preferred stock and warrants 1,442 — — Weighted-average common shares outstanding (diluted) 36,207 33,946 33,489 Basic net income (loss) per share $ 0.01 $ (0.04 ) $ (0.21 ) Diluted net income (loss) per share $ 0.01 $ (0.04 ) $ (0.21 )
Anti-Dilutive Securities Excluded from Calculation of Diluted Earnings Per Share	The anti-dilutive securities, which are excluded from the calculation of diluted earnings per share due to the Company’s net loss position for the periods then ended (including securities that would otherwise be excluded from the calculation of diluted earnings per share due the Company’s stock price), are as follows (in thousands): Fiscal Year December 31, 2016 January 2, 2016 January 3, 2015 Common stock warrants 20 50 50 Series A Convertible Preferred Stock 4,150 4,150 4,150 Options to purchase common stock 2,142 5,941 5,467 Restricted Stock Units — 839 796 Total 6,312 10,980 10,463

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Components of Loss Before Income Taxes	The components of loss before income tax provision consist of the following: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Domestic operations $ (1,305 ) $ (3,718 ) $ (7,424 ) Foreign operations 503 483 476 Total loss before income taxes $ (802 ) $ (3,235 ) $ (6,948 )
Summary of Income Tax (Benefit) Provision	Income tax (benefit) provision for fiscal year 2016 , 2015 and 2014 consists of the following: Fiscal Year Ended December 31, 2016 January 2, 2016 January 3, 2015 Current: Federal tax $ — $ — $ — State tax 7 7 (15 ) Foreign tax 162 88 78 Total current taxes 169 95 63 Deferred: Federal tax (331 ) (1,887 ) (2,232 ) State tax (616 ) 591 (125 ) Foreign tax — 61 74 Total deferred taxes (947 ) (1,235 ) (2,283 ) Valuation allowance 579 329 2,358 Income tax (benefit) provision $ (199 ) $ (811 ) $ 138
Summary of Differences Between Income Tax Provision (Benefit) and Applied Federal Statutory Rate	Income tax (benefit) provision differs from the amount that would result from applying the federal statutory rate as follows: December 31, 2016 January 2, 2016 January 3, 2015 Income tax at U.S. federal statutory rate $ (273 ) $ (1,100 ) $ (2,362 ) Share-based compensation 316 50 33 State income tax, net of federal tax effect (559 ) 672 (143 ) Foreign tax 20 (18 ) 117 Basis difference in subsidiary equity (267 ) (820 ) — Other (15 ) 76 127 Change in valuation allowance 579 329 2,366 Effective tax (benefit) provision $ (199 ) $ (811 ) $ 138
Summary of Deferred Tax Assets and Deferred Tax Liabilities	Deferred tax assets and deferred tax liabilities consisted of the following: December 31, 2016 January 2, 2016 Deferred tax assets: Inventory and inventory related allowance $ 839 $ 976 Share-based compensation 5,083 4,924 Amortization 7,636 9,244 Sales and bad debt allowances 749 443 Vacation accrual 224 220 Book over tax amortization — 31 Net operating loss and AMT credit carry-forwards 33,026 30,254 Other 800 843 Total deferred tax assets 48,357 46,935 Valuation Allowance (46,775 ) (46,196 ) Net deferred tax assets 1,582 739 Deferred tax liabilities: Investment in subsidiary — 368 Tax over book depreciation 1,518 639 Foreign tax withholdings — 470 Prepaid catalog expenses 64 100 Total deferred tax liabilities 1,582 1,577 Net deferred tax liabilities $ — $ (838 )
Summary of State NOL Carryforwards Expiration Year	The state NOL carryforwards expire in the respective tax years as follows: 2017 $ 6,930 2018 1,132 2019 7,646 2020 2,121 2021 4,050 Thereafter 61,148 $ 83,027

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Summary of Minimum Lease Commitments under Non-Cancelable Operating Leases	Minimum lease commitments under non-cancelable operating leases as of December 31, 2016 are as follows: 2017 $ 1,453 2018 1,493 2019 1,200 2020 550 2021 — Total 4,696
Summary of Capital Lease Commitments	The present value of the net minimum payments on capital leases as of December 31, 2016 is as follows: Total minimum lease payments $ 17,947 Less amount representing interest $ (7,635 ) Present value of net minimum lease payments 10,312 Current portion of capital leases payable (542 ) Capital leases payable, net of current portion $ 9,770 Capital lease commitments as of December 31, 2016 were as follows: Capital Lease Commitments Less: Interest Payments Principal Obligations 2017 $ 1,285 $ 743 $ 542 2018 1,319 721 598 2019 1,304 690 614 2020 1,129 657 472 2021 962 630 332 2022 onwards 11,948 4,194 7,754 Total $ 17,947 $ 7,635 $ 10,312

Restructuring Costs (Tables)

Restructuring Costs (Tables)	12 Months Ended
	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Summary of Restructuring Charges	The following table summarizes the charges related to the restructure recognized during the fiscal year ended January 3, 2015: Employee severance $ 526 Accounts receivable allowance 73 Relocation costs (employee and equipment) 127 Inventory transfers 411 Total restructuring costs $ 1,137

Quarterly Information (Unaudi35

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Consolidated Statement of Income Data	The following quarterly information (in thousands, except per share data) includes all adjustments which management considers necessary for a fair presentation of such information. For interim quarterly financial statements, the provision for income taxes is estimated using the best available information for projected results for the entire year. Quarter Ended Quarter Ended April 2, 2016 July 2, 2016 Oct. 1, 2016 Dec. 31, 2016 April 4, 2015 July 4, 2015 Oct. 3, 2015 Jan. 2, 2016 Consolidated Statement of Income Data: Net sales $ 80,806 $ 78,055 $ 73,515 $ 71,195 $ 76,388 $ 76,462 $ 70,648 $ 67,593 Gross profit 24,592 23,754 22,414 21,522 21,478 20,868 21,042 20,046 Income (loss) from operations 1,182 865 (84 ) (1,573 ) (18 ) (1,107 ) (222 ) (708 ) Income (loss) before income taxes 841 625 (367 ) (1,901 ) (368 ) (1,369 ) (491 ) (1,007 ) Net income (loss) 990 681 (360 ) (1,914 ) (316 ) (1,022 ) (288 ) (798 ) Net loss attributable to noncontrolling interests (262 ) (253 ) (258 ) (561 ) (256 ) (247 ) (296 ) (344 ) Net income (loss) attributable to U.S. Auto Parts $ 1,252 $ 934 $ (102 ) $ (1,353 ) $ (60 ) $ (775 ) $ 8 $ (454 ) Basic net income (loss) per share as reported and adjusted $ 0.03 $ 0.03 $ 0.00 $ (0.04 ) $ 0.00 $ (0.02 ) $ 0.00 $ (0.01 ) Diluted net income (loss) per share as reported and adjusted $ 0.03 $ 0.02 $ 0.00 $ (0.04 ) $ 0.00 $ (0.02 ) $ 0.00 $ (0.01 ) Shares used in computation of basic net income (loss) per share as reported and adjusted 34,497 34,753 34,932 34,878 33,720 33,963 34,018 34,084 Shares used in computation of diluted net income (loss) per share as reported and adjusted 39,359 40,007 34,932 34,878 33,720 33,963 34,018 34,084

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Summary of Segment Information	Summarized segment information for our continuing operations from the two reportable segments for the periods presented is as follows (in thousands): Base USAP AutoMD Consolidated Fiscal year ended December 31, 2016 Net sales $ 303,324 $ 247 $ 303,571 Gross profit 92,047 235 92,282 Operating costs (1) 87,782 4,110 91,892 Income (loss) from operations 4,265 (3,875 ) 390 Capital expenditures 5,414 939 6,353 Depreciation and amortization 6,351 1,159 7,510 Total assets, net of accumulated depreciation 78,094 4,040 82,134 Fiscal year ended January 2, 2016 Net sales $ 290,833 $ 258 $ 291,091 Gross profit 83,176 258 83,434 Operating costs (1) 82,044 3,445 85,489 Loss from operations 1,132 (3,187 ) (2,055 ) Capital expenditures 6,701 1,079 7,780 Depreciation and amortization 6,141 1,369 7,510 Total assets, net of accumulated depreciation 78,092 5,664 83,756 Fiscal year ended January 3, 2015 Net sales $ 283,211 $ 297 $ 283,508 Gross profit 78,153 297 78,450 Operating costs (1) 81,887 2,475 84,362 Loss from operations (3,734 ) (2,178 ) (5,912 ) Capital expenditures 4,237 1,319 5,556 Depreciation and amortization 7,230 1,693 8,923 Total assets, net of accumulated depreciation 74,414 8,493 82,907 (1) Operating costs for AutoMD primarily consist of depreciation on fixed assets and personnel costs. The following table summarizes the approximate distribution of Base USAP revenue by product type. 2016 2015 2014 Private Label Collision 51% 48% 43% Engine 15% 14% 13% Performance 1% 1% 1% Branded Collision 2% 2% 2% Engine 12% 14% 16% Performance 19% 21% 25% Total 100% 100% 100%

Summary of Significant Accoun37

Summary of Significant Accounting Policies and Nature of Operations - Principles of Consolidation (Details) - AutoMD - USD ($) $ in Thousands	Mar. 06, 2017	Jan. 26, 2017	Oct. 08, 2014	Oct. 31, 2016	Oct. 19, 2016
Subsidiary or Equity Method Investee [Line Items]
Percentage ownership after issuance of shares			64.10%	67.40%
Common Stock Purchase Agreement
Subsidiary or Equity Method Investee [Line Items]
Common stock issued (in shares)			7,000,000
Shares purchased (in shares)				2,000,000	2,000,000
Subsequent Event
Subsidiary or Equity Method Investee [Line Items]
Percentage ownership after issuance of shares		87.90%
Aggregate redeemed shares (in shares)		5,000,000
Purchase price	$ 1,194	$ 1,292
Percentage ownership of noncontrolling interests	12.10%

Summary of Significant Accoun38

Summary of Significant Accounting Policies and Nature of Operations - Additional Information (Detail)	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)	Oct. 01, 2016USD ($)	Jul. 02, 2016USD ($)	Apr. 02, 2016USD ($)	Jan. 02, 2016USD ($)	Oct. 03, 2015USD ($)	Jul. 04, 2015USD ($)	Apr. 04, 2015USD ($)	Dec. 31, 2016USD ($)suppliersegment	Jan. 02, 2016USD ($)	Jan. 03, 2015USD ($)
Property, Plant and Equipment [Line Items]
Percentage increase (decrease) in revenues									4.30%	2.70%
Net (loss) income	$ (1,353,000)	$ (102,000)	$ 934,000	$ 1,252,000	$ (454,000)	$ 8,000	$ (775,000)	$ (60,000)	$ 731,000	$ (1,281,000)	$ (6,879,000)
Other-than-temporary impairment charges on investments									$ 0
Number of suppliers products are available from (more than) | supplier									1
Inventory in-transit	9,767,000				12,241,000				$ 9,767,000	12,241,000
Capitalized website and software development costs									83,000	146,000	196,000
Impairment loss on intangible assets	1,130,000								$ 1,130,000	0	0
Impairment loss on property and equipment										$ 0	$ 0
Catalog amortization period									9 months
Advertising revenue as a percentage of total revenue									1.00%	1.00%	1.00%
Credits for returned products									$ 23,876,000	$ 23,543,000	$ 24,903,000
Warranty, coverage period									30 days
Warranty, unlimited product replacement, coverage period									5 years
Warranty, one-time product replacement, coverage period									5 years
Warranty, one-time product replacement, coverage period 1									3 years
Advertising costs									$ 22,616,000	20,251,000	18,485,000
Unrecognized tax benefits, interest or penalties	0								$ 0
Number of reportable segments | segment									2
Number of operating segments | segment									2
Minimum
Property, Plant and Equipment [Line Items]
Standard product warranty, recognition period									1 year
Maximum
Property, Plant and Equipment [Line Items]
Standard product warranty, recognition period									5 years
Website and Software Development
Property, Plant and Equipment [Line Items]
Capitalized website and software development costs									$ 4,977,000	5,664,000
Capitalized website and software development cost amount	22,366,000				22,745,000				22,366,000	22,745,000
Capitalized website and software development costs accumulated amortization and impairment amount	18,520,000				17,669,000				$ 18,520,000	17,669,000
Website and Software Development | Minimum
Property, Plant and Equipment [Line Items]
Amortization on a straight-line basis, period									2 years
Website and Software Development | Maximum
Property, Plant and Equipment [Line Items]
Amortization on a straight-line basis, period									3 years
Other Current Assets
Property, Plant and Equipment [Line Items]
Deferred catalog expenses	$ 160,000				$ 256,000				$ 160,000	256,000
Cost of Sales
Property, Plant and Equipment [Line Items]
Freight and shipping expenses									$ 41,937,000	$ 41,250,000	$ 40,428,000
Employee Stock Option | Minimum
Property, Plant and Equipment [Line Items]
Stock options vesting period									3 years
Employee Stock Option | Maximum
Property, Plant and Equipment [Line Items]
Stock options vesting period									4 years
Accumulated Deficit
Property, Plant and Equipment [Line Items]
Net (loss) income									$ 731,000

Summary of Significant Accoun39

Summary of Significant Accounting Policies and Nature of Operations - Allowance for Sales Returns and Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Allowance for sales returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 1,009	$ 897	$ 893
Charged to Revenue, Cost or Expenses	23,804	23,655	24,907
Deductions	(23,876)	(23,543)	(24,903)
Balance at End of Period	937	1,009	897
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	17	41	213
Charged to Revenue, Cost or Expenses	254	29	64
Deductions	(235)	(53)	(236)
Balance at End of Period	$ 36	$ 17	$ 41

Summary of Significant Accoun40

Summary of Significant Accounting Policies and Nature of Operations - Aggregate Warranty Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Warranty liabilities, beginning of period	$ 110	$ 218
Adjustments to preexisting warranty liabilities	0	(109)
Additions to warranty liabilities	918	53
Reductions to warranty liabilities	(139)	(52)
Warranty liabilities, end of period	$ 889	$ 110

Short-term investments - Securi

Short-term investments - Securities and Investments, Recorded at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	$ 32	$ 65
Unrealized Gains	0	0
Unrealized Losses	(2)	0
Fair Value	$ 30	$ 65

Short-term investments - Additi

Short-term investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Investments Schedule [Abstract]
Recognized gross realized loss from the sale of mutual funds	$ 0	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets Valued on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 6,673	$ 5,602
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	6,673	5,602
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Market Approach Valuation | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	6,643	5,537
Market Approach Valuation | Short-term investments – mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	30	65
Market Approach Valuation | Level 1 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	6,643	5,537
Market Approach Valuation | Level 1 | Short-term investments – mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	30	65
Market Approach Valuation | Level 2 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Market Approach Valuation | Level 2 | Short-term investments – mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Market Approach Valuation | Level 3 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Market Approach Valuation | Level 3 | Short-term investments – mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers into level 2 from level 1 assets	$ 0	$ 0	$ 0
Transfers into level 1 from level 2 assets	0	0	0
Impairment loss on intangible assets	$ 1,130,000	$ 1,130,000	$ 0	$ 0

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) $ in Thousands	Apr. 17, 2013USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2016USD ($)	Jan. 02, 2016USD ($)	Jan. 03, 2015USD ($)
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense			$ 7,510	$ 7,510	$ 8,923
Impairment loss on intangible assets		$ 1,130	1,130	0	$ 0
Property and equipment, gross carrying value		52,266	52,266	53,161
Property and equipment, accumulated depreciation		(35,788)	(35,788)	(34,730)
Property and equipment, net		16,478	16,478	18,431
Philippines
Property, Plant and Equipment [Line Items]
Property and equipment, net		367	$ 367	302
Capital Leased Assets (Facility)
Property, Plant and Equipment [Line Items]
Excess of net proceeds over the net carrying value of capital leased asset under sale and lease back	$ 376
Estimated useful life of property and equipment	20 years		20 years
Property and equipment, gross carrying value		11,306	$ 11,306	11,543
Property and equipment, accumulated depreciation		(2,273)	(2,273)	(1,839)
Property and equipment, net		$ 9,033	9,033	$ 9,704
LaSalle, Illinois Facility
Property, Plant and Equipment [Line Items]
Amortization expense related to capital leased asset			$ 475
Period of lease under sale and lease back transaction	20 years
Initial base annual rent for first year	$ 853
Percentage of annual increase in base rent	1.50%
Increased percentage in base rent with change in consumer price index	1.25
LaSalle, Illinois Facility | Whitney Automotive Group (WAG)
Property, Plant and Equipment [Line Items]
Gross proceeds from sale of La Salle, Illinois facility	$ 9,750
Net proceeds from sale of La Salle, Illinois facility	$ 9,507

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 52,266	$ 53,161
Less accumulated depreciation and amortization	(35,788)	(34,730)
Property and equipment, net	16,478	18,431
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	630	630
Building
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,877	8,877
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,368	12,334
Computer software (purchased and developed)
Property, Plant and Equipment [Line Items]
Property and equipment, gross	26,717	27,083
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	98	136
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,007	1,474
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,030	1,039
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,539	$ 1,588

Property and Equipment, Net -47

Property and Equipment, Net - Summary of Estimated Useful Lives of Property and Equipment (Detail)	Apr. 17, 2013	Dec. 31, 2016
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		2 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		5 years
Computer software (purchased and developed) | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		2 years
Computer software (purchased and developed) | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		3 years
Computer equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		2 years
Computer equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		5 years
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		3 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		5 years
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		3 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		5 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment		7 years
Capital Leased Assets (Facility)
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	20 years	20 years

Intangible Assets, Net - Additi

Intangible Assets, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense relating to intangible assets	$ 507	$ 464	$ 422

Intangible Assets, Net - Summar

Intangible Assets, Net - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,719	$ 4,719
Accumulated Amort. and Impairment	(3,750)	(3,243)
Net Carrying Amount	$ 969	1,476
Product design intellectual property
Finite-Lived Intangible Assets [Line Items]
Useful Life	4 years
Gross Carrying Amount	$ 2,750	2,750
Accumulated Amort. and Impairment	(2,620)	(2,361)
Net Carrying Amount	130	389
Patent license agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	562	562
Accumulated Amort. and Impairment	(368)	(219)
Net Carrying Amount	$ 194	343
Domain and trade names
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 years
Gross Carrying Amount	$ 1,407	1,407
Accumulated Amort. and Impairment	(762)	(663)
Net Carrying Amount	$ 645	$ 744
Minimum | Patent license agreements
Finite-Lived Intangible Assets [Line Items]
Useful Life	3 years
Maximum | Patent license agreements
Finite-Lived Intangible Assets [Line Items]
Useful Life	5 years

Intangible Assets, Net - Summ50

Intangible Assets, Net - Summary of Future Estimated Annual Amortization Expense (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 319
2,018	185
2,019	100
2,020	100
2,021	100
Thereafter	165
Net Carrying Amount	$ 969	$ 1,476

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($)	Dec. 31, 2016	Nov. 15, 2016	Dec. 31, 2016	May 06, 2016	Jan. 02, 2016
Line of Credit Facility [Line Items]
Revolving loan payable	$ 0		$ 0		$ 11,759,000
Minimum availability required trigger amount (if less than)		$ 2,400,000
Number of consecutive days excess availability is above required amount		45 days
Total capital leases payable	10,312,000		10,312,000
JPMorgan Chase Bank | Revolving Line of Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 30,000,000
Revolving loan payable	0		0
Line of Credit Facility, Exposure Amount		20,000,000		$ 15,000,000
Letters of Credit Outstanding, Amount	$ 11,658,000		$ 11,658,000
Maximum aggregate principal amount of indebtedness allowed for capital lease obligations		3,500,000		$ 2,000,000
Minimum availability required trigger amount (if less than)		$ 3,600,000
Consecutive business days below minimum excess availability		3 days
Number of consecutive days excess availability is above required amount		60 days
Unused capacity commitment fee percentage	0.25%
Limited security by foreign subsidiaries' capital stock percentage			65.00%
One-Month London Interbank Offered Rate (LIBOR) | JPMorgan Chase Bank | Revolving Line of Credit Facility
Line of Credit Facility [Line Items]
Applicable margin for LIBOR-based interest rate/ Applicable margin for Alternate base rate			1.25%
London Interbank Offered Rate (LIBOR) | JPMorgan Chase Bank | Revolving Line of Credit Facility
Line of Credit Facility [Line Items]
Interest rate	2.06%		2.06%
LIBOR based interest rate, principal	$ 0
Base Rate | JPMorgan Chase Bank | Revolving Line of Credit Facility
Line of Credit Facility [Line Items]
Applicable margin for LIBOR-based interest rate/ Applicable margin for Alternate base rate			0.25%
Interest rate	3.50%		3.50%
Prime based rate principal	$ 0

Borrowings - Present Value of N

Borrowings - Present Value of Net Minimum Payments on Capital Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Debt Disclosure [Abstract]
Total minimum lease payments	$ 17,947
Less amount representing interest	(7,635)
Total	10,312
Current portion of capital leases payable	(542)	$ (521)
Capital leases payable, net of current portion	$ 9,770	$ 10,168

Stockholders' Equity and Shar53

Stockholders' Equity and Share-Based Compensation - Schedule of Changes in Company's Ownership Interest in AutoMD (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Net income (loss) attributable to U.S. Auto Parts stockholders'	$ (1,353)	$ (102)	$ 934	$ 1,252	$ (454)	$ 8	$ (775)	$ (60)	$ 731	$ (1,281)	$ (6,879)
Transfers (to) from the noncontrolling interest:
Increase in U.S. Auto Parts paid-in-capital from sale of AutoMD common stock									0	0	2,512
Changes from net income (loss) attributable to U.S. Auto Parts stockholders' and transfers to noncontrolling interest									$ 731	$ (1,281)	$ (4,367)

Stockholders' Equity and Shar54

Stockholders' Equity and Share-Based Compensation - Common Stock (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	100,000,000	100,000,000
Shares of common stock issued from option exercises	442,000	301,000
Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in connection with preferred stock dividends (in shares)	37,000	103,000	83,000
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	100,000,000
Shares of common stock issued from option exercises	442,000	301,000	144,000
Issuance of common stock in connection with preferred stock dividends (in shares)	37,000	103,000	107,000
Issuance of common stock in connection with service fees	3,000	2,000
Common Stock | Series A Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in connection with preferred stock dividends (in shares)	37,000
Employee Stock Option | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued from option exercises	442,000
Restricted Stock Units (RSUs) | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued from option exercises	439,000
Performance Stock Units | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued from option exercises	10,000
Non-Employee Member Of The Board Of Directors | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in connection with service fees	3,000

Stockholders' Equity and Shar55

Stockholders' Equity and Share-Based Compensation - Treasury Stock (Details) - USD ($) $ / shares in Units, shares in Thousands	Dec. 31, 2016	Nov. 15, 2016
Class of Stock [Line Items]
Shares repurchased (in shares)	445
Average price (in USD per share)	$ 3.09
Aggregate purchase price	$ 1,376,000
Common Stock | Stock Repurchase Program, November 2016
Class of Stock [Line Items]
Shares authorized for purchase (up to) (in shares)		$ 5,000,000

Stockholders' Equity and Shar56

Stockholders' Equity and Share-Based Compensation - Series A Convertible Preferred Stock (Details) - Series A Convertible Preferred Stock	Apr. 05, 2013USD ($)shares	Mar. 25, 2013USD ($)$ / sharesshares	Dec. 31, 2016USD ($)vote$ / sharesshares	Jan. 02, 2016USD ($)$ / sharesshares	Jan. 03, 2015USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Series A convertible preferred stock, shares authorized | shares		4,150,000	4,150,000	4,150,000
Aggregate shares to be sold | shares		4,150,000
Series A convertible preferred stock, par value | $ / shares		$ 0.001	$ 0.001	$ 0.001
Preferred stock purchase price per share | $ / shares		$ 1.45
Preferred stock purchase, amount		$ 6,017,000
Preferred stock sold | shares	150,000	4,000,000
Aggregate proceeds of preferred stock	$ 217,000	$ 5,800,000
Issuance costs incurred to company	$ 847,000
Conversion rate of common stock for each share of Series A preferred stock | shares			1
Consecutive trading days for calculating weighted average price for the common stock			30 days
Minimum common stock price for consecutive thirty trading days for stock conversion | $ / shares			$ 4.35
Percentage of changes of control of company and sales or other dispositions by company (more than)			50.00%
Amount per share to series A preferred in case of liquidation (in dollars per share) | $ / shares			$ 1.45	$ 1.45
Preferred stock annual dividend rate (in dollars per share) | $ / shares			$ 0.058
Votes per share | vote			1
Cash dividends on amended credit			$ 400,000
Dividends			$ 241,000	$ 241,000	$ 240,000
Issuance of common stock in connection with preferred stock dividends (in shares) | shares			37,000	103,000	83,000
Common stock dividends during the period			$ 61,000	$ 0	$ 0

Stockholders' Equity and Shar57

Stockholders' Equity and Share-Based Compensation - Share-Based Compensation Plan Information (Details) - USD ($) $ / shares in Units, $ in Thousands	May 31, 2016	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of options granted (in dollars per share)		$ 1.65	$ 1.19	$ 1.34
Intrinsic value, options exercised		$ 599	$ 346	$ 153
Unrecognized share-based compensation expense		$ 1,344
Weighted-average period of unrecognized compensation expense		2 years 4 months 2 days
Shares related to the net settlement of the stock options		0	112,000
2016 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized to issued under condition one	2,500,000
Shares available for future grants (in shares)	3,894,000	6,307,000
Share reserve increase period (in shares)	9 years
Share reserve (in shares)	1,500,000
Expiration period	10 years
Option grant vesting period	4 years
Exercise price of option grants	100.00%
2007 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized to issued under condition one		1,500,000
Shares available for future grants (in shares)		0
Expiration period		10 years
Option grant vesting period		4 years
Exercise price of option grants		100.00%
Common stock authorized (in shares)		2,400,000
Maximum percentage of shares authorized to issued under condition one		5.00%
2007 New Employee Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)		0
Expiration period		10 years
Option grant vesting period		4 years
Exercise price of option grants		100.00%
Common stock authorized (in shares)		2,000,000
2006 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)		0
Equity Incentive Plan 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of options granted (in dollars per share)		$ 0.55	$ 0.55	$ 0.56
Unrecognized share-based compensation expense		$ 224
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld to satisfy employees' tax obligation (in shares)		0	27,000
Employees' tax obligation		$ 0	$ 80
Employee Stock Option | Equity Incentive Plan 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)		1,000
Weighted-average period of unrecognized compensation expense		2 years 2 months 12 days

Stockholders' Equity and Shar58

Stockholders' Equity and Share-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Shares
Outstanding, beginning (in shares)	5,841	5,281
Granted (in shares)	1,000	1,315
Exercised (in shares)	(442)	(301)
Cancelled:
Forfeited (in shares)	(149)	(256)
Expired (in shares)	(122)	(198)
Outstanding, ending (in shares)	6,128	5,841
Vested and expected to vest (in shares)	5,658	5,285
Exercisable (in shares)	4,220	3,735
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share)	$ 2.80	$ 2.85
Granted (in dollars per share)	3.03	2.24
Exercised (in dollars per share)	2.06	1.45
Cancelled:
Forfeited (in dollars per share)	2.47	2.06
Expired (in dollars per share)	7.66	3.31
Outstanding, ending (in dollars per share)	2.81	2.80
Vested and expected to vest (in dollars per share)	2.82	2.88
Exercisable (in dollars per share)	$ 2.92	$ 3.21
Outstanding, weighted average contractual term	5 years 8 months 27 days	6 years 11 days
Vested and expected to vest, weighted average contractual term	5 years 5 months 27 days	5 years 8 months 27 days
Exercisable, weighted average contractual term	4 years 5 months 27 days	4 years 6 months 15 days
Outstanding, aggregate intrinsic value	$ 6,561	$ 4,333
Vested and expected to vest, aggregate intrinsic value	6,111	3,853
Exercisable, aggregate intrinsic value	$ 4,618	$ 2,479

Stockholders' Equity and Shar59

Stockholders' Equity and Share-Based Compensation - Summary of Stock Option Activity for AutoMD (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Shares
Outstanding, beginning (in shares)	5,841	5,281
Granted (in shares)	1,000	1,315
Exercised (in shares)	(442)	(301)
Cancelled:
Forfeited (in shares)	(149)	(256)
Expired (in shares)	(122)	(198)
Outstanding, ending (in shares)	6,128	5,841
Vested and expected to vest (in shares)	5,658	5,285
Exercisable (in shares)	4,220	3,735
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share)	$ 2.80	$ 2.85
Granted (in dollars per share)	3.03	2.24
Exercised (in dollars per share)	2.06	1.45
Cancelled:
Forfeited (in dollars per share)	2.47	2.06
Expired (in dollars per share)	7.66	3.31
Outstanding, ending (in dollars per share)	2.81	2.80
Vested and expected to vest (in dollars per share)	2.82	2.88
Exercisable (in dollars per share)	$ 2.92	$ 3.21
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average contractual term	5 years 8 months 27 days	6 years 11 days
Vested and expected to vest, weighted average contractual term	5 years 5 months 27 days	5 years 8 months 27 days
Exercisable, weighted average contractual term	4 years 5 months 27 days	4 years 6 months 15 days
Outstanding, aggregate intrinsic value	$ 6,561	$ 4,333
Vested and expected to vest, aggregate intrinsic value	6,111	3,853
Exercisable, aggregate intrinsic value	$ 4,618	$ 2,479
Equity Incentive Plan 2014
Shares
Outstanding, beginning (in shares)	1,430	180
Granted (in shares)	10	1,250
Exercised (in shares)	0	0
Cancelled:
Forfeited (in shares)	(35)	0
Expired (in shares)	0	0
Outstanding, ending (in shares)	1,405	1,430
Vested and expected to vest (in shares)	1,044	1,061
Exercisable (in shares)	632	49
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share)	$ 1	$ 1
Granted (in dollars per share)	1	1
Exercised (in dollars per share)	0	0
Cancelled:
Forfeited (in dollars per share)	1	0
Expired (in dollars per share)	0	0
Outstanding, ending (in dollars per share)	1	1
Vested and expected to vest (in dollars per share)	1	1
Exercisable (in dollars per share)	$ 1	$ 1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average contractual term	8 years 2 months 12 days	9 years 2 months 7 days
Vested and expected to vest, weighted average contractual term	8 years 2 months 9 days	9 years 2 months 7 days
Exercisable, weighted average contractual term	8 years 1 month 21 days	8 years 11 months 1 day
Outstanding, aggregate intrinsic value		$ 0
Vested and expected to vest, aggregate intrinsic value		0
Exercisable, aggregate intrinsic value		$ 0

Stockholders' Equity and Shar60

Stockholders' Equity and Share-Based Compensation - Restricted Stock Units (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Mar. 03, 2017	Dec. 31, 2016	Jan. 02, 2016	Feb. 29, 2016	Jan. 21, 2016	Jul. 28, 2015	Jun. 23, 2015	May 20, 2015	Mar. 23, 2015	Jan. 29, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period of unrecognized compensation expense		2 years 4 months 2 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted		954	435
Closing price of grant (in dollars per share)				$ 2.75	$ 2.64	$ 2.18	$ 2.23	$ 2.33	$ 2.18	$ 2.29
Compensation expense		$ 1,626
Unrecognized compensation expense		$ 600
Weighted-average period of unrecognized compensation expense		7 months 17 days
Time-Based RSU Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted		382
Vested (in shares)			348
Awards forfeited			57
Unvested (in shares)			30
Performance-based RSU Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted		572
Minimum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period		1 year
Maximum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period		3 years
Subsequent Event | Performance-based RSU Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	525
Awards forfeited	47

Stockholders' Equity and Shar61

Stockholders' Equity and Share-Based Compensation - Stock Option Exchange Program (Details) $ / shares in Units, shares in Thousands, $ in Thousands	Sep. 10, 2013USD ($)employee$ / sharesshares	Aug. 12, 2013$ / sharesshares	Dec. 31, 2016$ / shares	Jan. 02, 2016$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised (in dollars per share)			$ 2.06	$ 1.45
Stock Option Exchange Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised (in dollars per share)		$ 4
Share exchange ratio per share		3.5
Shares issued under exchange program | shares		3,733
Stock options vesting period	4 years	4 years
Contractual term		10 years
Exercisable options | shares	3,475
Stock options exercised, weighted average exercise price (in dollars per share)	$ 6.65
Eligible employees | employee	45
Unvested exercisable options | shares	993
Unvested exercisable options exercise price (in dollars per share)	$ 0.9866
Incremental fair value on the date of exchange | $	$ 422
Stock Option Exchange Program | Stock Options Vesting in Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vested, percentage		25.00%
Stock Option Exchange Program | Stock Options Vesting After Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period		36 months
Stock options vested, percentage		75.00%
Minimum | Stock Option Exchange Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price, minimum		$ 4.01
Maximum | Stock Option Exchange Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price, maximum		$ 11.68

Stockholders' Equity and Shar62

Stockholders' Equity and Share-Based Compensation - Summary of Assumptions Used for Fair Value of Surrendered Stock Options and New Stock Options (Detail)	12 Months Ended
	Dec. 31, 2016
Surrendered Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%
Surrendered Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	1 year 11 months 4 days
Risk-free interest rate	0.50%
Expected volatility	55.00%
Surrendered Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 years 10 months 13 days
Risk-free interest rate	2.40%
Expected volatility	73.00%
New Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	5 years 10 months 2 days
Risk-free interest rate	2.00%
Expected volatility	72.00%
Expected dividend yield	0.00%

Stockholders' Equity and Shar63

Stockholders' Equity and Share-Based Compensation - Warrants (Details) - USD ($)	May 05, 2009	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015	Aug. 08, 2016	Apr. 27, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period of unrecognized compensation expense		2 years 4 months 2 days
Unrecognized share-based compensation expense		$ 1,344,000
Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in dollars per share)	$ 2.14					$ 8.32
Expiration period	7 years
Aggregate intrinsic value for warrants outstanding and exercisable		0
Compensation expense		0	$ 0	$ 0
Unrecognized share-based compensation expense		$ 0
Warrants Issued | Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants (in shares)	30,000				10,000	20,000
Warrants to purchase to common stock, outstanding		20,000
Warrants to purchase common stock, exercisable		20,000

Stockholders' Equity and Shar64

Stockholders' Equity and Share-Based Compensation - Summary of Assumptions Used for Fair Value of Option Grant (Detail) - Option Grant	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	5 years 6 months 26 days	5 years 4 months 2 days	5 years 3 months 18 days
Risk-free interest rate	1.00%	1.00%	2.00%
Expected volatility	60.00%	59.00%	62.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	5 years 7 months 10 days	5 years 6 months 7 days	5 years 4 months 13 days
Risk-free interest rate	2.00%	2.00%	2.00%
Expected volatility	61.00%	60.00%	68.00%

Stockholders' Equity and Shar65

Stockholders' Equity and Share-Based Compensation - Summary of Share-based Compensation from Options, Warrants and Stock Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 3,131	$ 2,419	$ 2,371
Marketing expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	433	518	540
General and administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	2,111	1,614	1,476
Fulfillment expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	450	241	220
Technology expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 137	$ 46	$ 135

Stockholders' Equity and Shar66

Stockholders' Equity and Share-Based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts capitalized to internally-developed software	$ 83,000	$ 146,000	$ 196,000
Tax benefit valuation allowance recognized	$ 0	$ 0	$ 0
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revised estimated forfeiture rate	10.00%	10.00%	10.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revised estimated forfeiture rate	34.00%	34.00%	34.00%

Net Income (Loss) Per Share - C

Net Income (Loss) Per Share - Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Numerator:
Net income (loss) attributable to U.S. Auto Parts	$ (1,353)	$ (102)	$ 934	$ 1,252	$ (454)	$ 8	$ (775)	$ (60)	$ 731	$ (1,281)	$ (6,879)
Dividends on Series A Convertible Preferred Stock									(241)	(241)	(240)
Net income (loss) available to common shares									$ 490	$ (1,522)	$ (7,119)
Denominator:
Weighted-average common shares outstanding (basic) (in shares)	34,878	34,932	34,753	34,497	34,084	34,018	33,963	33,720	34,765	33,946	33,489
Common equivalent shares from common stock options, preferred stock and warrants (in shares)									1,442	0	0
Weighted-average common shares outstanding (diluted) (in shares)	34,878	34,932	40,007	39,359	34,084	34,018	33,963	33,720	36,207	33,946	33,489
Basic net income (loss) per share as reported and adjusted(in dollars per share)	$ (0.04)	$ 0	$ 0.03	$ 0.03	$ (0.01)	$ 0	$ (0.02)	$ 0	$ 0.01	$ (0.04)	$ (0.21)
Diluted net income (loss) per share (in dollars per share)	$ (0.04)	$ 0	$ 0.02	$ 0.03	$ (0.01)	$ 0	$ (0.02)	$ 0	$ 0.01	$ (0.04)	$ (0.21)

Net Income (Loss) Per Share - A

Net Income (Loss) Per Share - Anti-Dilutive Securities Excluded from Calculation of Diluted Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted earnings per share	6,312	10,980	10,463
Series A Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted earnings per share	4,150	4,150	4,150
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted earnings per share	20	50	50
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted earnings per share	2,142	5,941	5,467
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted earnings per share	0	839	796

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 08, 2014	Oct. 31, 2016	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Tax Credit Carryforward [Line Items]
Effective tax rate			24.80%	25.10%	(2.00%)
Annual usage limitation			$ 135
Deferred tax liability as a result of transaction			0	$ 368
Valuation allowance			46,775	46,196
Accrued expenses related to income taxes payable			35	12
Federal
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards			75,261
State
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards			83,027
Whitney Automotive Group (WAG) | Federal
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards			2,690
AutoMD
Tax Credit Carryforward [Line Items]
Percentage ownership after issuance of shares	64.10%	67.40%
Deferred tax liability as a result of transaction			1,335
AutoMD | Federal
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards			7,506
Common Stock Purchase Agreement | AutoMD
Tax Credit Carryforward [Line Items]
Common stock issued (in shares)	7,000,000
Other non-current liabilities | Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Income taxes payable			$ 525	$ 470	$ 409

Income Taxes - Components of Lo

Income Taxes - Components of Loss Before Income Tax Provision (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Income Tax Disclosure [Abstract]
Domestic operations									$ (1,305)	$ (3,718)	$ (7,424)
Foreign operations									503	483	476
Loss before income taxes	$ (1,901)	$ (367)	$ 625	$ 841	$ (1,007)	$ (491)	$ (1,369)	$ (368)	$ (802)	$ (3,235)	$ (6,948)

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax (Benefit) Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Current:
Federal tax	$ 0	$ 0	$ 0
State tax	7	7	(15)
Foreign tax	162	88	78
Total current taxes	169	95	63
Deferred:
Federal tax	(331)	(1,887)	(2,232)
State tax	(616)	591	(125)
Foreign tax	0	61	74
Total deferred taxes	(947)	(1,235)	(2,283)
Valuation allowance	579	329	2,358
Income tax (benefit) provision	$ (199)	$ (811)	$ 138

Income Taxes - Summary of Diffe

Income Taxes - Summary of Differences Between Income Tax Provision (Benefit) and Applied Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Income Tax Disclosure [Abstract]
Income tax at U.S. federal statutory rate	$ (273)	$ (1,100)	$ (2,362)
Share-based compensation	316	50	33
State income tax, net of federal tax effect	(559)	672	(143)
Foreign tax	20	(18)	117
Basis difference in subsidiary equity	(267)	(820)	0
Other	(15)	76	127
Change in valuation allowance	579	329	2,366
Income tax (benefit) provision	$ (199)	$ (811)	$ 138

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Deferred tax assets:
Inventory and inventory related allowance	$ 839	$ 976
Share-based compensation	5,083	4,924
Amortization	7,636	9,244
Sales and bad debt allowances	749	443
Vacation accrual	224	220
Book over tax amortization	0	31
Net operating loss and AMT credit carry-forwards	33,026	30,254
Other	800	843
Total deferred tax assets	48,357	46,935
Valuation Allowance	(46,775)	(46,196)
Net deferred tax assets	1,582	739
Deferred tax liabilities:
Investment in subsidiary	0	368
Tax over book depreciation	1,518	639
Foreign tax withholdings	0	470
Prepaid catalog expenses	64	100
Total deferred tax liabilities	1,582	1,577
Net deferred tax liabilities	$ 0	$ (838)

Income Taxes - Summary of State

Income Taxes - Summary of State NOL Carryforwards Expiration Year (Detail) - State $ in Thousands	Dec. 31, 2016USD ($)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 83,027
2,017
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	6,930
2,018
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,132
2,019
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	7,646
2,020
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	2,121
2,021
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	4,050
Thereafter
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 61,148

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	Feb. 04, 2016USD ($)ft²	Apr. 17, 2013USD ($)	Mar. 01, 2010USD ($)	Dec. 31, 2016USD ($)	Jan. 02, 2016USD ($)	Jan. 03, 2015USD ($)
Other Commitments [Line Items]
Facility rent expense				$ 1,670	$ 1,555	$ 1,895
Property and equipment				$ 16,478	18,431
Capital Leased Assets (Facility)
Other Commitments [Line Items]
Estimated useful life of property and equipment		20 years		20 years
Property and equipment				$ 9,033	9,704
Chesapeake, Virginia | Warehouse
Other Commitments [Line Items]
Area of real estate property | ft²	159,294
Initial lease term	3 years
Base rent commitment	$ 640			53
Annual escalation, percentage	2.50%
Lease renewal term	3 years
Philippines
Other Commitments [Line Items]
Property and equipment				$ 367	$ 302
Philippines | Commercial Office Space
Other Commitments [Line Items]
Annual escalation, percentage			5.00%
Lease renewal term			60 months
Monthly lease rent			$ 25
Lease escalation beginning period			3 years
Nia Chloe | Sol Khazani
Other Commitments [Line Items]
Facility rent expense						$ 378
STORE | LaSalle, Illinois Facility
Other Commitments [Line Items]
Period of lease under sale and lease back transaction		20 years
Initial base annual rent for first year		$ 853
Percentage of annual increase in base rent		1.50%
Increased percentage in base rent with change in consumer price index		1.25
Excess of net proceeds over the net carrying value of capital leased asset under sale and lease back		$ 376
STORE | LaSalle, Illinois Facility | Capital Leased Assets (Facility)
Other Commitments [Line Items]
Estimated useful life of property and equipment		20 years

Commitments and Contingencies76

Commitments and Contingencies - Summary of Minimum Lease Commitments under Non-Cancelable Operating Leases (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,017	$ 1,453
2,018	1,493
2,019	1,200
2,020	550
2,021	0
Total	$ 4,696

Commitments and Contingencies77

Commitments and Contingencies - Summary of Capital Lease Commitments (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Capital Lease Commitments
2,017	$ 1,285
2,018	1,319
2,019	1,304
2,020	1,129
2,021	962
2022 onwards	11,948
Total	17,947
Less: Interest Payments
2,017	743
2,018	721
2,019	690
2,020	657
2,021	630
2022 onwards	4,194
Total	7,635
Principal Obligations
2,017	542
2,018	598
2,019	614
2,020	472
2,021	332
2022 onwards	7,754
Total	$ 10,312

Employee Retirement Plan and 78

Employee Retirement Plan and Deferred Compensation Plan - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2010	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Compensation and Retirement Disclosure [Abstract]
Minimum service period required to cover under plan		1 month
Employer's match per dollar of participants salary		$ 0.50
Employer's match percentage of participants salary		6.00%
Contributions vest in annual installments		3 years
Discretionary contributions		$ 289,000	$ 280,000	$ 256,000
Highly Compensated Employees
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Participant deferral of base salary, percentage (up to)	90.00%
Participant deferral of annual earned bonus, percentage (up to)	100.00%
Deferred compensation plan vested	100.00%
Employer contribution percentage of eligible participants eligible contribution	50.00%
Employer matching contribution, percentage of participants eligible contributions	2.00%
Increase (decrease) in deferred compensation, employee contribution		156,000	102,000
Increase (decrease) in deferred compensation, employer contribution		69,000	27,000
Increase (decrease) in deferred compensation, earnings		41,000	13,000
Increase (decrease) in deferred compensation, distributions		23,000	307,000
Gain (loss) on change in cash surrender value		2,000	73,000
Other non-current assets | Highly Compensated Employees
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Deferred compensation plan assets		676,000	781,000
Other non-current liabilities | Highly Compensated Employees
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Deferred compensation plan associated liabilities		$ 688,000	$ 558,000

Restructuring Costs (Detail)

Restructuring Costs (Detail) - Base USAP - Fiscal 2014	Jul. 25, 2014employee	Jan. 03, 2015USD ($)warehouse	Jan. 03, 2015USD ($)warehouse
Restructuring Cost and Reserve [Line Items]
Number of remaining warehouses | warehouse		2	2
Facility Closure | Carson, California
Restructuring Cost and Reserve [Line Items]
Headcount reduction, number of employees | employee	77
Inventory transfers | Cost of Sales
Restructuring Cost and Reserve [Line Items]
Inventory not deemed economically transferable			$ 130,000
Inventory write-down			767,000
Aggregate inventory charge			897,000
Employee severance
Restructuring Cost and Reserve [Line Items]
Severance payable		$ 0	$ 0
Employee severance | Fulfillment Expense
Restructuring Cost and Reserve [Line Items]
Reduction in severance charges		$ 26,000

Restructuring Costs - Summary o

Restructuring Costs - Summary of Restructuring Charges (Details) - Base USAP - Fiscal 2014 $ in Thousands	12 Months Ended
	Jan. 03, 2015USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,137
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs	526
Accounts receivable allowance
Restructuring Cost and Reserve [Line Items]
Restructuring costs	73
Relocation costs (employee and equipment)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	127
Inventory transfers
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 411

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	Mar. 06, 2017	Oct. 08, 2014	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Related Party Transaction [Line Items]
Facility rent expense			$ 1,670	$ 1,555	$ 1,895
Nia Chloe | Directors
Related Party Transaction [Line Items]
Facility rent expense					378
Nia Chloe | Directors | Lease Agreement
Related Party Transaction [Line Items]
Facility rent expense					$ 378
Oak | Directors
Related Party Transaction [Line Items]
Common stock issued (in shares)		1.5
Purchase price of shares issued (in dollars per share)		$ 1
Trust | Directors
Related Party Transaction [Line Items]
Common stock issued (in shares)		0.5
Purchase price of shares issued (in dollars per share)		$ 1
Subsequent Event | Oak | Affiliated Entity
Related Party Transaction [Line Items]
Stock redeemed (in shares)	1.5
Purchase price	$ 895
Subsequent Event | Trust | Affiliated Entity
Related Party Transaction [Line Items]
Stock redeemed (in shares)	0.5
Purchase price	$ 299

Quarterly Information (Unaudi82

Quarterly Information (Unaudited) - Consolidated Statement of Income Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 71,195	$ 73,515	$ 78,055	$ 80,806	$ 67,593	$ 70,648	$ 76,462	$ 76,388	$ 303,571	$ 291,091	$ 283,508
Gross profit	21,522	22,414	23,754	24,592	20,046	21,042	20,868	21,478	92,282	83,434	78,450
Income (loss) from operations	(1,573)	(84)	865	1,182	(708)	(222)	(1,107)	(18)	390	(2,055)	(5,912)
Income (loss) before income taxes	(1,901)	(367)	625	841	(1,007)	(491)	(1,369)	(368)	(802)	(3,235)	(6,948)
Net income (loss)	(1,914)	(360)	681	990	(798)	(288)	(1,022)	(316)	(603)	(2,424)	(7,086)
Net loss attributable to noncontrolling interests	(561)	(258)	(253)	(262)	(344)	(296)	(247)	(256)	(1,334)	(1,143)	(207)
Net income (loss) attributable to U.S. Auto Parts	$ (1,353)	$ (102)	$ 934	$ 1,252	$ (454)	$ 8	$ (775)	$ (60)	$ 731	$ (1,281)	$ (6,879)
Basic net income (loss) per share as reported and adjusted(in dollars per share)	$ (0.04)	$ 0	$ 0.03	$ 0.03	$ (0.01)	$ 0	$ (0.02)	$ 0	$ 0.01	$ (0.04)	$ (0.21)
Diluted net income (loss) per share as reported and adjusted (in dollars per share)	$ (0.04)	$ 0	$ 0.02	$ 0.03	$ (0.01)	$ 0	$ (0.02)	$ 0	$ 0.01	$ (0.04)	$ (0.21)
Shares used in computation of basic net income (loss) per share as reported and adjusted (in shares)	34,878	34,932	34,753	34,497	34,084	34,018	33,963	33,720	34,765	33,946	33,489
Shares used in computation of diluted net income (loss) per share as reported and adjusted (in shares)	34,878	34,932	40,007	39,359	34,084	34,018	33,963	33,720	36,207	33,946	33,489

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2016segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Summary o

Segment Information - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Segment Reporting Information [Line Items]
Net sales	$ 71,195	$ 73,515	$ 78,055	$ 80,806	$ 67,593	$ 70,648	$ 76,462	$ 76,388	$ 303,571	$ 291,091	$ 283,508
Gross profit	21,522	22,414	23,754	24,592	20,046	21,042	20,868	21,478	92,282	83,434	78,450
Operating costs									91,892	85,489	84,362
Income (loss) from operations	(1,573)	$ (84)	$ 865	$ 1,182	(708)	$ (222)	$ (1,107)	$ (18)	390	(2,055)	(5,912)
Capital expenditures									6,353	7,780	5,556
Depreciation and amortization expense									7,510	7,510	8,923
Total assets, net of accumulated depreciation	82,134				83,756				82,134	83,756	82,907
Base USAP
Segment Reporting Information [Line Items]
Net sales									303,324	290,833	283,211
Gross profit									92,047	83,176	78,153
Operating costs									87,782	82,044	81,887
Income (loss) from operations									4,265	1,132	(3,734)
Capital expenditures									5,414	6,701	4,237
Depreciation and amortization expense									6,351	6,141	7,230
Total assets, net of accumulated depreciation	78,094				78,092				78,094	78,092	74,414
AutoMD
Segment Reporting Information [Line Items]
Net sales									247	258	297
Gross profit									235	258	297
Operating costs									4,110	3,445	2,475
Income (loss) from operations									(3,875)	(3,187)	(2,178)
Capital expenditures									939	1,079	1,319
Depreciation and amortization expense									1,159	1,369	1,693
Total assets, net of accumulated depreciation	$ 4,040				$ 5,664				$ 4,040	$ 5,664	$ 8,493

Segment Information - Summary85

Segment Information - Summary of Segment Percentages (Details) - Sales Revenue, Product Line - Product Concentration Risk - Reportable Segments - Base USAP	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Segment Reporting Information [Line Items]
Percent of revenue	100.00%	100.00%	100.00%
Private Label Collision
Segment Reporting Information [Line Items]
Percent of revenue	51.00%	48.00%	43.00%
Private Label Engine
Segment Reporting Information [Line Items]
Percent of revenue	15.00%	14.00%	13.00%
Private Label Performance
Segment Reporting Information [Line Items]
Percent of revenue	1.00%	1.00%	1.00%
Branded Collision
Segment Reporting Information [Line Items]
Percent of revenue	2.00%	2.00%	2.00%
Branded Engine
Segment Reporting Information [Line Items]
Percent of revenue	12.00%	14.00%	16.00%
Branded Performance
Segment Reporting Information [Line Items]
Percent of revenue	19.00%	21.00%	25.00%

AutoMD (Details)

AutoMD (Details) - AutoMD $ / shares in Units, $ in Thousands	Mar. 06, 2017USD ($)minority_shareholder	Jan. 26, 2017USD ($)shares	Oct. 08, 2014board_member$ / sharesshares	Oct. 31, 2016shares	Oct. 19, 2016$ / sharesshares
Common Stock Purchase Agreement
Noncontrolling Interest [Line Items]
Common stock issued			7,000,000
Purchase price of shares issued (in dollars per share) | $ / shares			$ 1
Number of shares the Company may be required to purchase (in shares)				2,000,000	2,000,000
Purchase price (in dollars per share) | $ / shares					$ 1
Common Stock Purchase Agreement | Directors
Noncontrolling Interest [Line Items]
Number of board members affiliated with the transaction | board_member			2
Subsequent Event
Noncontrolling Interest [Line Items]
Aggregate redeemed shares (in shares)		5,000,000
Purchase price | $	$ 1,194	$ 1,292
Number of minority stockholders | minority_shareholder	2