Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity and Share-Based Compensation - Additional Information (Details)

v2.4.1.9
Stockholders' Equity and Share-Based Compensation - Additional Information (Details) (USD $)
 12 Months Ended
Jan. 03, 2015
Dec. 28, 2013
Dec. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Amounts capitalized to internally-developed software $ 196,000us-gaap_CapitalizedComputerSoftwareAdditions $ 220,000us-gaap_CapitalizedComputerSoftwareAdditions $ 252,000us-gaap_CapitalizedComputerSoftwareAdditions
Tax benefit valuation allowance recognized $ 0us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense $ 0us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense $ 0us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Revised estimated forfeiture rate 16.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		16.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		16.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Revised estimated forfeiture rate 34.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		34.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		34.00%prts_RevisedEstimatedForfeitureRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember