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

Stockholders' Equity and Share-Based Compensation - Common Stock (Detail)	12 Months Ended
	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	100,000,000us-gaap_CommonStockSharesAuthorized	100,000,000us-gaap_CommonStockSharesAuthorized
Shares of common stock issued from option exercises	142,000
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)	83,000	24,000
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	100,000
Shares of common stock issued from option exercises	144,000	101,000	489,000
Issuance of common stock in connection with preferred stock dividends (in shares)	107,000	50,000
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)	107,000
Employee Stock Option \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued from option exercises	144,000
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	21

Number of share options (or share units) exercised during the current period.