v3.8.0.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2018
May 11, 2018
Document And Entity Information [Abstract]    
Entity Registrant Name Real Goods Solar, Inc.  
Entity Central Index Key 0001425565  
Trading Symbol rgse  
Current Fiscal Year End Date --12-31  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   10,620,107
Document Type 10-Q  
Document Period End Date Mar. 31, 2018  
Amendment Flag false  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1