v3.19.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2018
Apr. 10, 2019
Jun. 30, 2018
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 Non-accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Public Float     $ 8,926,996
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Amendment Flag false    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Shell Company false    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Ex Transition Period false    
Class A common stock      
Entity Common Stock, Shares Outstanding   108,902,754  
Class B common stock      
Entity Common Stock, Shares Outstanding   0