Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2018
Jun. 07, 2018
Sep. 30, 2017
Document and Entity Information [Abstract]      
Entity Registrant Name MOTORCAR PARTS AMERICA INC    
Entity Central Index Key 0000918251    
Current Fiscal Year End Date --03-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Accelerated Filer    
Entity Public Float     $ 553,613,587
Entity Common Stock, Shares Outstanding   18,893,102  
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Document Type 10-K    
Amendment Flag false    
Document Period End Date Mar. 31, 2018