v3.7.0.1
Document And Entity Information - shares
6 Months Ended
Jun. 30, 2017
Jul. 26, 2017
Document Information [Line Items]    
Entity Registrant Name ACELRX PHARMACEUTICALS INC  
Entity Central Index Key 0001427925  
Trading Symbol acrx  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Well-known Seasoned Issuer No  
Entity Common Stock, Shares Outstanding (in shares)   45,380,473
Document Type 10-Q  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Amendment Flag false