Annual report pursuant to Section 13 and 15(d)

Related-Party Transactions - Additional Information (Detail)

v2.4.1.9
Related-Party Transactions - Additional Information (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended 0 Months Ended
Jan. 03, 2015
Dec. 28, 2013
Dec. 29, 2012
Oct. 08, 2014
Related Party Transaction [Line Items]        
Lease payments and expenses $ 1,895us-gaap_LeaseAndRentalExpense $ 2,150us-gaap_LeaseAndRentalExpense $ 2,388us-gaap_LeaseAndRentalExpense  
Nia Chloe | Directors        
Related Party Transaction [Line Items]        
Lease payments and expenses 378us-gaap_LeaseAndRentalExpense
/ us-gaap_CounterpartyNameAxis
= prts_NiaChloeLLCMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
374us-gaap_LeaseAndRentalExpense
/ us-gaap_CounterpartyNameAxis
= prts_NiaChloeLLCMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
374us-gaap_LeaseAndRentalExpense
/ us-gaap_CounterpartyNameAxis
= prts_NiaChloeLLCMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
 
Nia Chloe | Directors | Lease Agreement        
Related Party Transaction [Line Items]        
Lease payments and expenses $ 378us-gaap_LeaseAndRentalExpense
/ us-gaap_CounterpartyNameAxis
= prts_NiaChloeLLCMember
/ us-gaap_RelatedPartyTransactionAxis
= us-gaap_LeaseAgreementsMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
$ 374us-gaap_LeaseAndRentalExpense
/ us-gaap_CounterpartyNameAxis
= prts_NiaChloeLLCMember
/ us-gaap_RelatedPartyTransactionAxis
= us-gaap_LeaseAgreementsMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
   
Oak | Directors        
Related Party Transaction [Line Items]        
Common stock issued       1,500,000us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
/ us-gaap_CounterpartyNameAxis
= prts_OakInvestmentPartnersXIL.P.Member
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
Trust | Directors        
Related Party Transaction [Line Items]        
Common stock issued       500,000us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
/ us-gaap_CounterpartyNameAxis
= prts_SolKhazaniLivingTrustMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember
Purchase price of shares issued       1.00us-gaap_SaleOfStockPricePerShare
/ us-gaap_CounterpartyNameAxis
= prts_SolKhazaniLivingTrustMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_DirectorMember