Document and Entity Information
3 Months Ended
Mar. 31, 2015
May 06, 2015
Document and Entity Information    
Entity Registrant Name PCM, INC.  
Entity Central Index Key 0000937941  
Document Type 10-Q  
Document Period End Date Mar. 31, 2015  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   12,050,001
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q1