Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2019
Jun. 19, 2019
Sep. 30, 2018
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 Shell Company false    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Ex Transition Period false    
Entity Public Float     $ 434,744,944
Entity Common Stock, Shares Outstanding   18,819,792  
Document Type 10-K    
Amendment Flag false    
Document Period End Date Mar. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY