v3.8.0.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2017
Mar. 30, 2018
Jun. 30, 2017
Entity Registrant Name Real Goods Solar, Inc.    
Entity Central Index Key 0001425565    
Trading Symbol rgse    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Current Fiscal Year End Date --12-31    
Entity Filer Category Smaller Reporting Company    
Entity Well-known Seasoned Issuer Yes    
Entity Public Float     $ 7,313,815
Document Type 10-K    
Document Period End Date Dec. 31, 2017    
Amendment Flag false    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Class A common stock      
Entity Common Stock, Shares Outstanding   10,351,845  
Class B common stock      
Entity Common Stock, Shares Outstanding   0