CarParts.com, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies and Nature of Operations - Additional Information (Detail)

Summary of Significant Accounting Policies and Nature of Operations - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended									12 Months Ended
	Oct. 31, 2012	Jan. 03, 2015	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 29, 2012	Jan. 03, 2015 supplier segment	Dec. 28, 2013	Dec. 29, 2012
Schedule Of Significant Accounting Policies [Line Items]
Percentage increase (decrease) in revenues											11.30%	(16.20%)
Net loss		$ 2,406,000us-gaap_NetIncomeLoss	$ 2,494,000us-gaap_NetIncomeLoss	$ 2,180,000us-gaap_NetIncomeLoss	$ (201,000)us-gaap_NetIncomeLoss	$ 1,325,000us-gaap_NetIncomeLoss	$ 1,399,000us-gaap_NetIncomeLoss	$ 9,567,000us-gaap_NetIncomeLoss	$ 3,343,000us-gaap_NetIncomeLoss		$ 6,879,000us-gaap_NetIncomeLoss	$ 15,634,000us-gaap_NetIncomeLoss	$ 35,978,000us-gaap_NetIncomeLoss
Other-than-temporary impairment charges on investments											0us-gaap_ImpairmentOfInvestments	0us-gaap_ImpairmentOfInvestments	0us-gaap_ImpairmentOfInvestments
Number of suppliers products are available from (more than)											1prts_NumberofSuppliers
Inventory		48,362,000us-gaap_InventoryNet				36,986,000us-gaap_InventoryNet					48,362,000us-gaap_InventoryNet	36,986,000us-gaap_InventoryNet
Inventory in-transit		12,155,000us-gaap_OtherInventoryInTransit				6,750,000us-gaap_OtherInventoryInTransit					12,155,000us-gaap_OtherInventoryInTransit	6,750,000us-gaap_OtherInventoryInTransit
Capitalized website and software development costs											196,000	220,000	252,000
Impairment loss on property and equipment								4,832,000		1,960,000	0	4,832,000	1,960,000
Impairment loss on intangible assets subject to amortization								1,245,000		1,745,000
Excess of carrying value over fair value	21,843,000
Impairment loss on goodwill	18,854,000us-gaap_GoodwillImpairmentLoss										0us-gaap_GoodwillImpairmentLoss	0us-gaap_GoodwillImpairmentLoss	18,854,000us-gaap_GoodwillImpairmentLoss
Fair value inputs, discount rate								14.50%us-gaap_FairValueInputsDiscountRate
Impairment loss on indefinite lived intangible assets										3,868,000
Goodwill						0us-gaap_Goodwill						0us-gaap_Goodwill
Indefinite-lived intangible assets						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											24,903,000us-gaap_SalesReturnsGoods	24,618,000us-gaap_SalesReturnsGoods	30,420,000us-gaap_SalesReturnsGoods
Limited warranty description											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.
Standard product warranties, coverage period (or greater than)											30 days
Extended product warranty description											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.
Five year unlimited product replacement, coverage period											5 years
Five year one-time product replacement period, coverage period											5 years
Three year one-time product replacement period, coverage period											3 years
Advertising costs											18,485,000us-gaap_AdvertisingExpense	16,619,000us-gaap_AdvertisingExpense	21,068,000us-gaap_AdvertisingExpense
Unrecognized tax benefits, interest or penalties		0									0
Number of reportable segments											2us-gaap_NumberOfReportableSegments
Number of operating segments											2us-gaap_NumberOfOperatingSegments
Trade Names
Schedule Of Significant Accounting Policies [Line Items]
Fair value inputs, discount rate													15.00%
Royalty rate													0.10%
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Standard product warranty, recognition period											1 year
Maximum
Schedule Of Significant Accounting Policies [Line Items]
Standard product warranty, recognition period											5 years
Website and Software Development
Schedule Of Significant Accounting Policies [Line Items]
Capitalized website and software development costs											5,651,000	8,150,000
Capitalized website and software development cost amount		40,757,000				50,250,000					40,757,000	50,250,000
Capitalized website and software development costs accumulated amortization and impairment amount		36,060,000				44,211,000					36,060,000	44,211,000
Capitalized websites and software development costs impairment loss											4,832,000	3,868,000
Website and Software Development \| Minimum
Schedule Of Significant Accounting Policies [Line Items]
Amortization on a straight-line basis, period											2 years
Website and Software Development \| Maximum
Schedule Of Significant Accounting Policies [Line Items]
Amortization on a straight-line basis, period											3 years
Other Current Assets
Schedule Of Significant Accounting Policies [Line Items]
Deferred catalog expenses		441,000				485,000					441,000	485,000
Cost of Sales
Schedule Of Significant Accounting Policies [Line Items]
Freight and shipping expenses											$ 40,428,000	$ 34,182,000	$ 39,702,000
Employee Stock Option \| Minimum
Schedule Of Significant Accounting Policies [Line Items]
Stock options vesting period											3 years
Employee Stock Option \| Maximum
Schedule Of Significant Accounting Policies [Line Items]
Stock options vesting period											4 years